JP2021175075A - Program and mail server - Google Patents

Abstract

To provide a program and a mail server that can reduce the processing load of a cloud-type mail server and quickly deliver an e-mail to the destination by avoiding centralized delivery to the cloud-type mail server when a cloud-type mail service is used.SOLUTION: A host of a MX record is obtained from a DNS server on the basis of the domain of the destination of an e-mail. An e-mail is adjusted when a host string contains a string indicating a cloud-type mail server.SELECTED DRAWING: Figure 5

Description

The present invention relates to a program and a mail server.

In recent years, cloud-based email services are often used for the convenience of users. From the user's point of view, the cloud-based email service has the advantage that it can be accessed from any terminal as long as the login information is known, and the email can be easily checked. In addition, for the mail administrator, the cloud-type mail service has merits such as no trouble of operating the mail server and less trouble even in the event of a disaster.

In addition, as a conventional technique, there is a mail server that uses a connection pool technology to provide a program and a mail server that can reduce the processing load of the mail server and shorten the processing time of e-mail delivery (). Patent Document 1).

Japanese Unexamined Patent Publication No. 2016-72809

The mail server makes an inquiry to the DNS server (DNS stands for "Domain Name System"; the same applies hereinafter) based on the destination domain, and the IP address of the connection destination (delivery destination) (IP is "Internet protocol (IP)". Abbreviation of "Internet Protocol"). The same shall apply hereinafter), establish a communication path for communication with the mail server of the IP address, and deliver the e-mail.

When using a cloud-type mail service, the mail server that provides the cloud-type mail service (hereinafter referred to as a cloud-type mail server) intensively accepts a large amount of e-mails, which imposes an excessive processing load. It may take. As a result, when an e-mail is delivered from the delivery source mail server to the cloud-type mail server, the cloud-type mail server refuses to accept the e-mail delivered from the delivery source mail server. There was a problem that mail could not be delivered promptly.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to avoid centralized delivery to a cloud-type mail server when using a cloud-type mail service. It is an object of the present invention to provide a program and a mail server capable of reducing the processing load of the e-mail and promptly delivering the e-mail to the destination.

(1) The present invention
A program for mail servers that deliver email
A reception unit that processes e-mails and
A host acquisition unit that acquires the host of the MX record from the DNS server based on the domain of the destination of the e-mail, and
A determination unit that determines whether or not the e-mail is to be adjusted based on the host.
When the e-mail is to be adjusted, the computer is made to function as a delivery unit that adjusts the delivery timing of the e-mail and delivers the e-mail.
The determination unit
The present invention relates to a program characterized in that when the character string of the host includes a character string indicating a cloud-type mail server, the e-mail is to be adjusted.

The present invention also relates to an information storage medium that stores the above program and a mail server that is configured as each of the above parts.

According to the present invention, when a host based on the domain of the destination of the e-mail is acquired and the character string of the host includes the character string indicating the cloud-type mail server, the e-mail is adjusted, so that the cloud-type When using the mail service, it is possible to avoid centralized delivery of e-mail to the cloud-type mail server, and as a result, the processing load of the cloud-type mail server is reduced and the e-mail is quickly addressed. It will be possible to deliver to.

(2) Further, the program, information storage medium and mail server of the present invention are
The determination unit
Even if the character string of the domain to which the e-mail is sent does not include the character string indicating the cloud type mail server, the character string of the host includes the character string indicating the cloud type mail server. E-mail may be subject to adjustment.

If the character string of the domain to which the e-mail is sent does not include the character string indicating the cloud-type mail server, it is clear that the company does not operate the mail server and uses the cloud-type mail service. In such a case, the present invention can control the e-mail using the cloud-type mail service so as to be surely adjusted.

(3) Further, the program, information storage medium and mail server of the present invention are
The delivery department
For the e-mail to be adjusted, at least one of the delivery interval and the number of e-mails delivered at the same time may be adjusted for delivery.

According to the present invention, at least one of the delivery interval and the number of e-mails delivered at the same time is adjusted for delivery, so that an appropriate delivery timing can be adjusted.

(4) Further, the program, information storage medium and mail server of the present invention are
The delivery department
For the e-mail to be adjusted, at least one of the process of shortening the delivery interval according to the passage of time and the process of increasing the number of deliveries according to the passage of time may be performed.

According to the present invention, it is possible to adjust the delivery timing so as to gradually apply a load to the cloud-type mail server, and it is possible to make an adjustment in consideration of the balance between the delivery efficiency and the processing load. can.

(5) Further, the program, information storage medium and mail server of the present invention are
Based on the host acquired by the host acquisition unit, the connection destination address acquisition unit that acquires the connection destination address from the DNS server, and the connection destination address acquisition unit.
A connection pool unit that holds a connection to the connection destination address that was connected when delivering the e-mail, and a connection pool unit.
When the connection to the connection destination address is held, the process of associating the domain of the e-mail, the host acquired by the host acquisition unit, and the connection destination address and storing them in the storage unit is performed. Make the computer function further as a connection information management unit to perform
The host acquisition unit
Get the host of the MX record based on the domain of the newly accepted email destination,
The delivery department
When the domain of the destination of the newly received e-mail is stored in the storage unit, the process of delivering the e-mail using the connection of the connection destination address corresponding to the domain.
When a host acquired based on the domain of the destination of the newly received e-mail is stored in the storage unit, the process of delivering the e-mail using the connection of the connection destination address corresponding to the host. ,
When the connection destination address acquired based on the host is stored in the storage unit, at least one process of delivering the e-mail using the connection of the connection destination address may be performed. good.

Here, the connection destination address is an address on the network of the mail server of the delivery destination for delivering the e-mail, and for example, in order to identify the device on the network by the IP address (IP such as IPv4 and IPv6). Identification number in the specified network layer).

According to the present invention, when the domain of the destination of the newly received e-mail, the host acquired based on the domain, or the connection destination address acquired based on the host is stored in the storage unit. , Since the e-mail can be delivered by omitting some processing (for example, connection processing), the processing load of the mail server can be reduced.

(6) Further, the program, information storage medium and mail server of the present invention are
The determination unit
When the character string of the host includes a character string indicating a cloud-type mail server, the e-mail is targeted for adjustment for the cloud.
If the character string of the host does not include the character string indicating the cloud-type mail server, the e-mail is subject to other adjustment.
The delivery department
When the e-mail is to be adjusted for the cloud, the delivery timing of the e-mail is adjusted and delivered based on the adjustment information for the cloud.
When the e-mail is to be adjusted for another purpose, the delivery timing of the e-mail may be adjusted and delivered based on the other adjustment information.

According to the present invention, it is possible to make adjustments for the cloud and other adjustments for the delivery of e-mails, and it is possible to reduce the processing load in a well-balanced manner according to the delivery destination.

An example of a network diagram of this embodiment. An example of a functional block diagram of the mail server of this embodiment. The explanatory view of the process which determines whether or not the e-mail of this embodiment is subject to adjustment. The figure for demonstrating the delivery of the adjustment target e-mail of this embodiment. The flowchart of the process of this embodiment.

Hereinafter, this embodiment will be described. The present embodiment described below does not unreasonably limit the content of the present invention described in the claims. Moreover, not all of the configurations described in the present embodiment are essential constituent requirements of the present invention.

[1] Network FIG. 1 is an example of a network diagram of the present embodiment. The mail server 10 of the present embodiment is an MTA (Mail Transfer Agent) that accepts (receives) and delivers e-mails on a network via SMTP.

The mail server 10 receives an e-mail consisting of an envelope destination (destination e-mail address) used for delivery processing, an envelope sender (sender e-mail address), and a message, and receives the e-mail via the network. Performs delivery to the delivery destination mail server (destination mail server) based on the destination of the envelope.

More specifically, the mail server 10 accepts an e-mail sent from an MUA (Mail User Agent). The MUA is a client program used to send and receive e-mails on a terminal on the Internet.

Next, the mail server 10 sends the received e-mail to the DNS server that manages the destination domain of the envelope of the received e-mail, the DNS server in the local area of the mail server 10, or another DNS server. Queries the MX record host for the destination domain of the envelope. For example, the mail server 10 queries the DNS server for the MX record of the destination domain and acquires the host of the destination domain.

Then, when the mail server 10 can acquire the host of the MX record of the domain of the destination of the envelope of the received e-mail, the mail server 10 inquires about the IP address of the host. If the mail server cannot acquire the host of the MX record of the domain of the destination of the envelope of the received e-mail, the mail server designates the domain as the host and inquires about the IP address. For example, the mail server 10 inquires of the DNS server for the A record of the host (AAAA record in the case of IPv6, the same applies hereinafter), and acquires the IP address of the host. That is, this IP address becomes the delivery destination address of the delivery destination mail server.

Then, the mail server 10 establishes a connection with the delivery destination mail server based on the IP address, and performs a process of delivering (delivering, transmitting, forwarding, relaying) the e-mail.

The mail server 10 of the present embodiment accepts e-mails including a case where an e-mail is received from a terminal through SMTP and a case where an e-mail delivered from another mail server is received through SMTP.

Further, when the mail server 10 of the present embodiment delivers an e-mail, it means that the received e-mail is delivered to another mail server through SNTP, or a user who has an account in the same system in which the mail server 10 operates. Includes a process of delivering to a local delivery agent MDA (Mail Delivery Agent) for delivering to, and a process of locally delivering to a user who has an account in the same system in which a mail server operates without going through an MDA.

[2] Mail Server Configuration FIG. 2 is an example of a functional block diagram of the mail server 10 of the present embodiment. The mail server 10 of the present embodiment does not need to include all the parts shown in FIG. 2, and a part thereof may be omitted.

The storage unit 170 serves as a work area for the processing unit 100 and the like, and its function can be realized by hardware such as RAM (VRAM).

The storage unit 170 of the present embodiment includes connection information 171. The connection information 171 is information on the pooled connection. The connection information is information in which the host is associated with the connection destination address (for example, the IP address of the connection destination mail server) acquired from the DNS server based on the host. The connection information may be information in which the domain is associated with the host acquired from the DNS server based on the domain and the connection destination address acquired from the DNS server based on the host.

The storage unit 170 may secure a spool area (storage area) for temporarily storing the e-mail received by the reception unit 111. The e-mail stored in the spool area is deleted from the spool area when the delivery process is completed (delivery ends normally or delivery error ends). When the delivery error ends, that is, the e-mail that cannot be delivered to the delivery destination mail server is stored in the spool area again.

Further, the information storage medium 180 can be read by a computer, and the information storage medium 180 stores programs, data, and the like. That is, the information storage medium 180 stores a program for operating the computer as each part of the present embodiment (a program for causing the computer to execute the processing of each part). That is, the processing unit 100 can perform various processes of the present embodiment based on the data read from the program (data) stored in the information storage medium 180.

For example, the information storage medium 180 is an optical disk (CD, DVD), a magneto-optical disk (MO), a magnetic disk, a hard disk, a magnetic tape, a memory (ROM), a memory card, or the like.

The processing unit 100 performs various processes of the present embodiment based on the program (data) stored in the storage unit 170. The processing unit 100 of the present embodiment reads out the program or data stored in the information storage medium 180, stores the read program or data in the storage unit 170, and performs processing based on the program or data. May be good.

The processing unit 100 (processor) performs various processes using the main storage unit in the storage unit 170 as a work area. The function of the processing unit 100 can be realized by hardware such as various processors (CPU, DSP, etc.) and a program.

The processing unit 100 includes a receiving unit 111, a host acquisition unit 112, a determination unit 113, a connection destination address acquisition unit 114, a connection pool unit 116, a connection information management unit 117, and a delivery unit 118.

The receiving unit 111 performs a process (processing of receiving) of receiving an e-mail transmitted from the sender and designated as the destination of the envelope by the MUA of the terminal (computer, mobile phone, tablet computer, smartphone).

The host acquisition unit 112 acquires the host of the MX record from the DNS server based on the domain of the e-mail destination.

The determination unit 113 determines whether or not the e-mail is to be adjusted based on the host acquired based on the domain of the destination of the e-mail by the host acquisition unit 112.

For example, the determination unit 113 sets the e-mail as the adjustment target (for example, the adjustment target for the cloud) when the character string of the host includes the character string indicating the cloud type mail server.

Further, the determination unit 113 sets the character string indicating the cloud type mail server as the character string of the host even when the character string of the domain of the e-mail destination does not include the character string indicating the cloud type mail server. If included, email will be adjusted.

Further, the determination unit 113 sets the e-mail as another adjustment target when the character string of the host does not include the character string indicating the cloud-type mail server.

For example, when the destination domain of the e-mail is a specific domain, the determination unit 113 determines the e-mail as the "adjustment target for the specific domain" e-mail.

For example, the determination unit 113 sets the e-mail as "default" when the character string of the host does not include the character string indicating the cloud-type mail server and the destination domain of the e-mail is not a specific domain. Judged as "adjustment target" e-mail.

The connection destination address acquisition unit 114 acquires the connection destination address from the DNS server based on the host acquired by the host acquisition unit 112.

The connection pool unit 116 performs a process of holding (maintaining) a connection to the connection destination address connected when delivering an e-mail. For example, the connection to the connection destination address is retained for a predetermined period (until a timeout occurs), and is disconnected after the predetermined period elapses.

Further, the connection pool unit 116 may hold a plurality of connections. For example, the connection to a plurality of the same or different destination addresses may be maintained.

When the connection information management unit 117 holds a connection to the connection destination address connected when delivering the e-mail, the destination domain, the host acquired by the host acquisition unit 112, and the connection destination address are used. , Are associated with each other and stored in the storage unit 170.

That is, the process of storing (registering) the host acquired by the host acquisition unit 112 and the connection destination address in the storage unit 170 as a set of connection information is performed.

The domain of the destination of the e-mail, the host of the MX record of the domain of the destination of the e-mail, and the connection destination address of the e-mail are stored (registered) in the storage unit 170 as a set of connection information. You may.

Further, when a plurality of connections are held, the connection information management unit 117 performs a process of storing the connection information in the storage unit for each connection.

The delivery unit 118 performs a process of delivering the received e-mail.

For example, the delivery unit 118 performs a process of delivering an e-mail by connecting to a connection destination address acquired from a DNS server based on the domain of the e-mail destination mail dress (or a host acquired based on the domain).

When the e-mail is to be adjusted, the delivery unit 118 adjusts the delivery timing of the e-mail and delivers the e-mail.

For example, the delivery unit 118 adjusts at least one of the delivery interval and the number of deliveries of the e-mails to be delivered at the same time for the e-mails to be adjusted. Further, the delivery unit 118 may perform at least one of a process of shortening the delivery interval according to the passage of time and a process of increasing the number of deliveries according to the passage of time for the e-mail to be adjusted. ..

Further, when the host acquired based on the domain of the destination of the newly received e-mail is stored in the storage unit 170, the delivery unit 118 uses the connection of the connection destination address corresponding to the host. The process of delivering the e-mail may be performed.

Further, when a new e-mail is received, the delivery unit 118 connects the connection destination address corresponding to the domain of the e-mail destination when the domain of the e-mail destination is stored in the storage unit 170. May be used to perform the process of delivering the e-mail.

Further, the delivery unit 118 acquires a host based on the domain of the newly received e-mail destination, further acquires a connection destination address based on the host, and the acquired connection destination address is stored in the storage unit 170. If it is stored, the process of delivering the e-mail may be performed using the connection of the connection destination address.

Further, when the e-mail is to be adjusted for the cloud, the delivery unit 118 adjusts the delivery timing of the e-mail based on the adjustment information for the cloud and delivers the e-mail.

Further, when the e-mail is to be adjusted for another, the delivery unit 118 adjusts the delivery timing of the e-mail based on the other adjustment information and delivers the e-mail.

For example, the delivery unit 118 adjusts the delivery timing and delivers the e-mail to be adjusted for the specific domain based on the predetermined “adjustment information for the specific domain” (an example of other adjustment information).

In addition, the delivery unit 118 adjusts the delivery timing and delivers the e-mail to be adjusted by default based on the predetermined "default adjustment information" (an example of other adjustment information).

[3] Outline of delivery When the mail server of the present embodiment receives an e-mail, it accesses the DNS server, inquires about the MX record of the destination domain of the envelope of the e-mail, and determines the host of the connection destination (delivery destination). get. Then, when the host can be acquired, the DNS server is inquired about the A record, and the connection destination address (for example, IP address) of the delivery destination host is acquired. The mail server uses TCP (Transmission) for the acquired IP address.
A connection is established by (Control Protocol), and the process of delivering an e-mail by SMTP is performed.

[4] Cloud-type mail server By the way, when operating a mail server with a system owned by the company, which has been the mainstream in the past (in the case of so-called on-premises), the administrator can set the mail server, set the communication line, and so on. It was necessary to secure a storage area (hardware) for storing e-mail, a device for operating a mail server, and to set services associated with these. In addition, the mail server operated in-house has disadvantages such as an initial cost and difficulty in recovery in the event of a disaster.

Therefore, in recent years, there are many companies and users who use cloud-type mail services that reduce the burden on the administrator. A mail server that provides a cloud-type mail service (hereinafter referred to as a cloud-type mail server) is controlled so that it can be accessed from any terminal connected to the Internet. For example, if a user logs in using the Web browser of the terminal, the user's e-mail information (e-mail transmission information and e-mail reception information) can be viewed, and the user creates an e-mail on the Web. You can also do it.

In the cloud-type mail service, the storage area (hardware) for storing e-mail, the device for operating the mail server, the mail server setting, the communication line setting, and the service settings associated with these are set in the cloud-type mail. It is on the service provider side, and the burden on the administrator is reduced. In addition, when using the cloud-type mail service, the administrator needs to perform simple setting work such as setting the host of the MX record for the DNS server for the company's domain.

[5] Delivery adjustment target In particular, the mail server 10 of the present embodiment determines whether or not the e-mail is to be adjusted based on the host acquired from the DNS server for the domain of the destination of the received e-mail. That is, when the mail server 10 determines whether or not the host is a host related to a predetermined cloud-type mail server, and if the host is determined to be a host related to a predetermined cloud-type mail server, the mail server 10 determines. The e-mail is subject to delivery adjustment.

[5.1] Acquisition of the host of the e-mail destination First, when the mail server 10 receives the e-mail, the mail server 10 selects the host of the e-mail destination of the MX record from the DNS server based on the domain of the e-mail destination. get.

For example, the mail server 10 accepts an e-mail having a message ID = 001, and the destination of the e-mail is "suzuki@ifyy.gr.jp". Then, the mail server 10 inquires about the host of the MX record from the DSN server based on the domain "ifyy.gr.jp". For example, the mail server 10 receives information that the host is "ppp1.zzz.com". The message ID is unique identification information assigned to identify the e-mail.

[5.2] Judgment process of whether or not the mail server is subject to adjustment Then, the mail server 10 uses a character string of the host (for example, "ppp1.zzz.com") acquired from the DNS server to indicate a cloud-type mail server. (For example, zzz.com) is included, the e-mail is subject to adjustment.

Here, the "character string indicating a cloud-type mail server" is a character string that can estimate the host that provides the cloud-type mail service. Further, the "character string indicating the cloud-type mail server" may be one or a plurality. When there are a plurality of "character strings indicating a cloud-type mail server" and the character string of the host obtained from the DNS server includes a character string indicating one of the cloud-type mail servers, the e-mail is to be adjusted. do.

The mail server 10 makes it possible to set a character string indicating a cloud-type mail server in advance based on the input information from the administrator. FIG. 3 shows an example of a character string 60 indicating a cloud-type mail server. For example, an administrator can use a computer to give a given command (eg, nslookup).
Based on up, dig, etc.), the character string of the MX record of the cloud-type mail server is acquired from the DNS server, and based on the operation input of the administrator, the original domain (for example, zzz.com) of the character string is set to ". Set as a "character string indicating a cloud-type mail server".

Further, "when the character string of the host acquired from the DNS server includes a character string indicating a cloud-type mail server" means, for example, a part of the character string of the host acquired from the DNS server (for example, the original domain part). However, it matches the character string indicating the predetermined cloud type mail server (partial match), or the character string itself of the host obtained from the DNS server matches the character string indicating the predetermined cloud type mail server. That (exact match), etc.

For example, as shown in FIG. 3, when the host acquired based on the domain "ifyy.gr.jp" of the e-mail destination "suzuki@ifyy.gr.jp" is "ppp1.zzz.com", the relevant case. Since the unique domain part "zzz.com" of the host "ppp1.zzz.com" matches the predetermined character string "zzz.com" indicating the cloud-type mail server, the e-mail is to be adjusted. Is determined.

As described above, according to the present embodiment, the character string (for example, ifyy.gr.jp) of the domain of the destination of the e-mail does not include the character string (for example, zzz.com) indicating the cloud-type mail server. Even in the case, if the character string of the host (for example, ppp1.zzz.com) contains the character string indicating the cloud-type mail server (for example, zzz.com), there is a partial match, so the e-mail is adjusted. set to target.

That is, according to the present embodiment, since it is determined whether or not to focus on the host and make the adjustment target, it is possible to control the e-mail using the cloud-type mail service so as to be surely made the adjustment target. ..

Further, as shown in FIG. 3, when the destination of the e-mail is "yamada@ifzzz.gr.jp" and the host of the domain is "zzz.com", the host "zzz.com" is previously set. Since it matches (exactly matches) the character string "zzz.com" indicating the defined cloud-type mail server, it is determined that the e-mail is to be adjusted.

When the destination of the e-mail is "tanaka@zzz.com" and the host of the domain is "zzz.com", the host "zzz.com" is a character indicating a predetermined cloud-type mail server. Since it matches (exactly matches) with "zzz.com" in the column, it is determined that the e-mail is to be adjusted. That is, in the mail server 10, the domain part of the destination of the e-mail eventually matches (partially or completely matches) the character string "zzz.com" indicating the cloud-type mail server, and the e-mail is concerned. May be determined to be the adjustment target.

[5.3] Delivery Process of E-mail to be Adjusted When the mail server 10 of the present embodiment is to be adjusted, the mail server 10 performs a process of adjusting the delivery timing of the e-mail and delivering it. In this way, the processing load of the mail server that provides the cloud-type mail service can be reduced, the situation where the delivery destination mail server refuses to deliver the e-mail is avoided, and the e-mail delivery error is reduced. can do.

"Adjusting the delivery timing" means, for example, adjusting the delivery timing and delivering the e-mail to be adjusted. The adjustment information is at least one of the delivery interval and the number of e-mails delivered at the same time.

When the character string of the host acquired from the DNS server based on the domain of the destination of the received e-mail includes the character string indicating the cloud-type mail server, the mail server 10 adjusts the e-mail for the cloud. Then, based on the adjustment information for the cloud, the delivery timing is adjusted and delivered.

The mail server 10 adjusts the delivery timing and delivers the e-mail to be adjusted for the cloud for each delivery destination mail server (for each cloud type mail server). Specifically, with reference to FIG. 4A, an example of delivery timing of five e-mails M1 to M5 to be adjusted whose delivery destination mail server (cloud type mail server) is “zzz.com” will be described. ..

For example, the mail server 10 has five e-mails M1 to M5 to be adjusted to be delivered to the cloud-type mail server of "zzz.com" as one aggregate. Then, the mail server 10 delivers the five adjusted e-mails M1 to M5 to be delivered to the cloud-type mail server (for example, zzz.com) at predetermined delivery intervals (for example, every 5 seconds). Deliver a number (eg, one) of adjusted emails.

For example, as shown in FIG. 4A, the mail server 10 delivers the e-mail M1 at the timing T1, delivers the e-mail M2 at the timing T2 5 seconds after the timing T1, and 5 seconds after the timing T2. The e-mail M3 is delivered at the timing T3 of the above, the e-mail M4 is delivered at the timing T4 5 seconds after the timing T3, and the e-mail M5 is delivered at the timing T5 5 seconds after the timing T4.

The mail server 10 may connect the e-mails M1 to M5 to the same connection destination address (for example, an IP address as shown in 211.259.95.188) for delivery, or may use different connection destination addresses. You may connect to and deliver. For example, the mail server 10 inquires the DNS server for the A record (connection destination address) of the host, but even if the host name is the same, a different connection destination address may be acquired.

The number of deliveries may be 2 or more. For example, when two e-mails to be adjusted are delivered at a predetermined delivery interval (for example, every 5 seconds), the two e-mails are delivered to the delivery destination in succession at the delivery timing without any interval. do.

Further, the mail server 10 may set the delivery interval and the number of deliveries based on the input of the administrator, or the mail server 10 may automatically set the delivery interval and the number of deliveries.

Further, the mail server 10 may perform at least one of a process of shortening the delivery interval according to the passage of time and a process of increasing the number of deliveries according to the passage of time for the e-mail to be adjusted. ..

For example, the mail server 10 sets the delivery interval to 20 seconds in the initial state of operation (at the start of operation), and shortens the delivery interval according to the passage of time. For example, the delivery interval is shortened by 1 second every time 1 hour elapses. Finally, the delivery interval may be set to 1 second.

Further, the mail server 10 may set the number of e-mails to be delivered at the same time based on the input of the administrator, or the mail server 10 may automatically set the number of e-mails to be delivered at the same time. You may.

For example, the mail server 10 sets the number of deliveries of e-mails to be delivered at the same time in the initial state of operation (at the start of operation) to one, and increases the number of deliveries as time passes. For example, the number of deliveries is increased by one every time one hour elapses. Finally, the number of deliveries may be set to 10.

[5.4] Parallel processing The mail server 10 may perform parallel processing on a plurality of adjusted e-mails having the same delivery destination mail server (cloud type mail server). The same delivery destination mail server may mean, for example, the same character string indicating a cloud-type mail server (for example, "zzz.com") or the host (for example, "ppp1.zzz.com"). ) May be the same.

Specifically, with reference to FIG. 4B, an example of delivery timing of 15 e-mails M1 to M15 to be adjusted whose delivery destination mail server (cloud type mail server) is “zzz.com” will be described. ..

For example, the mail server 10 has 15 e-mails M1 to M15 to be adjusted to be delivered to the cloud-type mail server of "zzz.com" as one aggregate. Then, the mail server 10 classifies the 15 e-mails M1 to M15 to be adjusted to be delivered to the cloud-type mail server (for example, zzz.com) into a plurality of (for example, three) groups. Then, a plurality of classified groups are delivered in parallel at a predetermined delivery interval (for example, every 5 seconds) to deliver the e-mails to be adjusted for the number of deliveries (for example, one). The e-mails M1 to M15 may be classified evenly, or may be classified by domain, host, and connection destination address (IP address).

For example, as shown in FIG. 4B, the mail server 10 uses M1 to M5 for 15 e-mails M1 to M15 to be adjusted to be delivered to a cloud-type mail server (for example, zzz.com). It is classified into a first group composed, a second group composed of M6 to M10, and a third group composed of M11 to M15. Then, each group delivers the e-mails to be adjusted for the number of deliveries (for example, one) at predetermined delivery intervals (for example, every 5 seconds). Further, the e-mails to be adjusted for the number of deliveries (for example, 1) are delivered at predetermined delivery intervals (for example, every 5 seconds) while shifting the delivery timing of each group by 1 second.

For example, when the e-mail M1 is delivered at the timing T1 for the first group, the e-mail M6 is delivered at the timing T11 one second after the timing T1 for the second group, and the e-mails M6 are delivered for the third group from the timings T11 to 1. At the timing T21 after a second, the e-mail M11 is delivered. In this way, it is possible to efficiently deliver the e-mail to the same delivery destination and reduce the processing load.

[6] Multi-step adjustment processing In the mail server 10 of the present embodiment, when the character string of the host acquired from the DNS server based on the domain of the destination of the received e-mail includes the character string indicating the cloud type mail server. , Determines the email as a "cloud adjustment target" email.

Then, when the character string of the host acquired from the DNS server based on the domain of the destination of the received e-mail does not include the character string indicating the cloud type mail server, the mail server 10 determines the domain in advance. Determine if it is a specific domain.

When the domain is a specific domain, the mail server 10 determines that the e-mail is an e-mail of "adjustment target for a specific domain" (an example of another adjustment target).

Then, the mail server 10 sets the e-mail that does not correspond to the adjustment target for the cloud and does not correspond to the adjustment target for the specific domain as the e-mail of the "default adjustment target" (an example of another adjustment target). judge. The default means a predetermined standard state (initial state).

In the present embodiment, as described above, the delivery timing of the email to be adjusted for the cloud is adjusted and delivered based on the adjustment information for the cloud. For example, a number of deliveries (eg, one) of e-mails are delivered at predetermined delivery intervals (eg, every 5 seconds).

Then, the mail server 10 adjusts the delivery timing and delivers the e-mail to be adjusted for the specific domain based on the predetermined "adjustment information for the specific domain" (an example of other adjustment information). For example, a number of deliveries (eg, 3) of emails are delivered at predetermined delivery intervals (eg, every 3 seconds). In this way, flexible delivery processing according to the domain can be performed.

Further, the mail server 10 adjusts the delivery timing and delivers the e-mail to be adjusted by default based on the predetermined "default adjustment information" (an example of other adjustment information). A number of deliveries (eg, 5) are delivered at predetermined delivery intervals (eg, 1 second intervals). By doing so, the default delivery timing can be adjusted, and the processing load of the entire mail server can be reduced in a well-balanced manner.

That is, according to the present embodiment, it is possible to perform stepwise adjustment, and it is possible to perform the delivery process of the e-mail in consideration of the processing load of the mail server 10 and the mail server of the delivery destination.

[7] Connection pool In the present embodiment, the connection once established retains (maintains, pools) the connection until a predetermined period determined in advance by the mail server 10 elapses, and delivers the e-mail using the connection. Processing may be performed.

For example, the mail server 10 acquires a host from the DNS server based on the domain of the destination of the e-mail, acquires the connection destination address from the DNS server based on the host, establishes a connection to the connection destination address, and then causes the mail server 10. Hold the connection for a specified period of time. While the mail server 10 holds the connection, the mail server 10 performs a process of associating the domain, the host, and the connection destination address and storing them in the storage unit 170.

The mail server 10 may hold the connection only when the host of the domain to which the e-mail is sent is a host indicating a predetermined cloud-type mail server.

Then, when the domain of the destination of the newly received e-mail is stored in the storage unit 170, the mail server 10 delivers the e-mail by using the connection of the connection destination address corresponding to the domain. I do. By doing so, the processing of acquiring the e-mail host and connection destination address and establishing the connection is omitted, so that the processing load of the mail server 10 can be reduced.

Further, when the host acquired based on the domain of the destination of the newly received e-mail is stored in the storage unit 170, the mail server 10 uses the connection of the connection destination address corresponding to the host. Performs the process of delivering the e-mail. By doing so, the processing of acquiring the connection destination address of the e-mail and establishing the connection is omitted, so that the processing load of the mail server 10 can be reduced.

Further, when the connection destination address acquired based on the host is stored in the storage unit 170, the mail server 10 performs a process of delivering the e-mail by using the connection of the connection destination address. By doing so, the processing of acquiring the connection destination address of the e-mail and establishing the connection is omitted, so that the processing load of the mail server 10 can be reduced.

If a plurality of connection destination addresses for the host of the domain of the newly received e-mail destination domain are stored in the storage unit 170, the mail server 10 is not delivering (vacant) any of the connection destinations. The process of delivering the e-mail is performed using the connection of the address.

[8] Flowchart Next, the flow of the delivery process of the mail server of the present embodiment will be described with reference to FIG. First, when the mail server 10 receives the e-mail (step S1), the destination domain is extracted (step S2), and the host of the MX record is acquired from the DNS server based on the extracted domain (step S3).

Then, it is determined whether or not the character string of the host includes the character string indicating the cloud-type mail server (step S4). When the character string of the host includes a character string indicating a cloud-type mail server (Y in step S4), a process of adjusting the delivery timing of the e-mail and delivering the e-mail based on the adjustment information for the cloud is performed (step). S5).

On the other hand, when the character string of the host does not include the character string indicating the cloud-type mail server (N in step S4), it is determined whether or not the destination domain is a specific domain (step S6). When the destination domain is a specific domain (Y in step S6), a process of adjusting the delivery timing of the e-mail and delivering it based on the adjustment information for the specific domain is performed (step S7).

Then, when the destination domain is not a specific domain (N in step S6), the delivery timing of the e-mail is adjusted and delivered based on the default adjustment information (step S8). This completes the process.

[9] Others The present invention is not limited to the one described in the above embodiment, and various modifications can be made. For example, a term cited as a broad or synonymous term in a description in a specification or drawing can be replaced with a broad or synonymous term in another description in the specification or drawing.

The present invention includes a configuration substantially the same as the configuration described in the embodiment (for example, a configuration having the same function, method and result, or a configuration having the same purpose and effect). The present invention also includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. In addition, the present invention includes a configuration that exhibits the same effects as the configuration described in the embodiment or a configuration that can achieve the same object. Further, the present invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

As described above, the embodiments of the present invention have been described in detail, but those skilled in the art will easily understand that many modifications that do not substantially deviate from the novel matters and effects of the present invention are possible. .. Therefore, all such modifications are included in the scope of the present invention.

10 mail server, 100 processing unit, 111 receiving unit, 112 host acquisition unit,
113 Judgment unit, 114 Connection destination address acquisition unit, 116 Connection pool unit,
117 Connection Information Management Department, 118 Delivery Department, 170 Storage Department,
171 Connection information, 180 Information storage medium

Claims (7)

A program for mail servers that deliver email
A reception unit that processes e-mails and
A host acquisition unit that acquires the host of the MX record from the DNS server based on the domain of the destination of the e-mail, and
A determination unit that determines whether or not the e-mail is to be adjusted based on the host.
When the e-mail is to be adjusted, the computer is made to function as a delivery unit that adjusts the delivery timing of the e-mail and delivers the e-mail.
The determination unit
A program characterized in that when the character string of the host includes a character string indicating a cloud-type mail server, the e-mail is adjusted. In claim 1,
The determination unit
Even if the character string of the domain to which the e-mail is sent does not include the character string indicating the cloud-type mail server, the character string of the host includes the character string indicating the cloud-type mail server. A program characterized by adjusting e-mail. In claim 1 or 2,
The delivery department
A program characterized in that the e-mail to be adjusted is delivered by adjusting at least one of the delivery interval and the number of e-mails delivered at the same time. In claim 3,
The delivery department
A program characterized by performing at least one of a process of shortening the delivery interval according to the passage of time and a process of increasing the number of deliveries according to the passage of time for the e-mail to be adjusted. In any of claims 1 to 4,
Based on the host acquired by the host acquisition unit, the connection destination address acquisition unit that acquires the connection destination address from the DNS server, and the connection destination address acquisition unit.
A connection pool unit that holds a connection to the connection destination address that was connected when delivering the e-mail, and a connection pool unit.
When the connection to the connection destination address is held, the process of associating the domain of the e-mail, the host acquired by the host acquisition unit, and the connection destination address and storing them in the storage unit is performed. Make the computer function further as a connection information management unit to perform
The host acquisition unit
Get the host of the MX record based on the domain of the newly accepted email destination,
The delivery department
When the domain of the destination of the newly received e-mail is stored in the storage unit, the process of delivering the e-mail using the connection of the connection destination address corresponding to the domain.
When a host acquired based on the domain of the destination of the newly received e-mail is stored in the storage unit, the process of delivering the e-mail using the connection of the connection destination address corresponding to the host. ,
When the connection destination address acquired based on the host is stored in the storage unit, at least one process of delivering the e-mail using the connection of the connection destination address is performed. Program to do. In any of claims 1 to 5,
The determination unit
When the character string of the host includes a character string indicating a cloud-type mail server, the e-mail is targeted for adjustment for the cloud.
If the character string of the host does not include the character string indicating the cloud-type mail server, the e-mail is subject to other adjustment.
The delivery department
When the e-mail is to be adjusted for the cloud, the delivery timing of the e-mail is adjusted and delivered based on the adjustment information for the cloud.
A program characterized in that when the e-mail is targeted for another adjustment, a process of adjusting the delivery timing of the e-mail and delivering the e-mail based on other adjustment information is performed. A storage unit that stores the program according to any one of claims 1 to 6.
A mail server comprising a processor for executing the program.

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