JP2009188960A - Electronic mail server having address change function with time limit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate a malfunction that the necessity of the prevention of an outflow of private information and troublesome mail arises highly together with the propagation of e-mail, and as a countermeasure for the malfunction, an use of temporary mail address is proposed, however, since the mail to a temporary mail address is sent to the original transmitter after all, it is not a thorough countermeasure, when making the mail from the specified original transmitter out of a subject, the control of each original transmitter address is necessary and the cancellation of operation is necessary. <P>SOLUTION: The effective prevention means of troublesome mail can specify the effective time limit of the temporary mail address, to eliminate the temporary mail address from a table when exceeding the time limit, and to discard the mail to the temporary mail address. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a technique for transmitting and receiving mail after converting an e-mail address to a temporary mail address.

  With the widespread use of the Internet, personal computers, and mobile phones, e-mail is now used as a more convenient means of communication than telephone. On the other hand, spam emails that users do not want to receive, such as virus emails and advertisement emails sent indiscriminately, are becoming a problem.

In addition, a service that distributes subscription-type information using e-mail is also popular, but membership registration is required to use this service, and personal information including e-mail addresses is notified to service providers. There is a need to. It is also a problem that e-mail addresses are leaked from this service provider and the like, and nuisance e-mails that registrants do not want to receive are inundated.

As one of countermeasures against such personal information leakage and junk mail, a method of converting a sender mail address into a temporary mail address in a mail server is known.

  For example, in Patent Document 1, for the purpose of preventing leakage of personal information including a sender email address, a sender email address of a received electronic mail is set as a temporary email address associated with the sender email address in a mail server or the like. When converting, registering, sending the e-mail source address replaced with the registered temporary e-mail address, and conversely, if the e-mail destination e-mail address received matches the registered temporary e-mail address, A technique is disclosed in which a destination email address is reversely converted to a source email address associated with a temporary email address.

  In Patent Document 2, for the purpose of preventing the reception of junk mail, a mail server or the like converts the transmission source mail address of the received electronic mail into a temporary mail address associated with the transmission destination mail address, registers the registration, The transmission source address of the e-mail is replaced with the registered temporary e-mail address and transmitted, and conversely, the e-mail address and the e-mail address of the received e-mail are registered and the temporary address of the transmission source. If the email address combination matches, the destination email address of the received e-mail is replaced with the source email address associated with the matched combination, and the destination requested to be rejected by the sender is sent. Delete the association between the email address and the temporary email address and make it the destination email address. When receiving the e-mail of a temporary email address registered from transmission not registered source discloses a technique of detecting as unauthorized source.

JP 2002-73475 A JP 2003-46579 A

However, the technique described in Patent Document 1 has no description regarding the update period and validity period of the temporary mail address, and the spam mail addressed to the temporary mail address is also transmitted to the sender mail address. There is a problem that it is not an email countermeasure.

In the case of the technique described in Patent Document 2, there is no description about the update period or validity period of the temporary mail address, and in order to reject reception from a specific mail address such as spam mail, the conventional reception rejection registration As with, there is a troublesome problem that the association between the temporary mail address and the destination mail address must be deleted. Furthermore, because each destination email address is registered in association with the destination email address and the temporary email address, the user deletes the number of destination email addresses and the number of temporary email addresses registered for each source email address. As long as it does not increase, it continues to increase, and as it increases, there is a problem of requiring a cumulatively large storage capacity.

The present invention has been made in view of the above circumstances, and an object of the present invention is to send a mail server or the like in association with a source mail address without modifying the original mail address used by the user. Issue and register a provisional e-mail address with a time limit for each e-mail so that you can automatically reject e-mails sent to expired temporary e-mail addresses. An object of the present invention is to provide an electronic mail server having an e-mail address conversion function with a time limit that can significantly reduce the storage capacity of the storage device by deleting.

  In order to solve the above-described problem, in the present invention, a transmission source email address of a transmission email from a registered user is converted into a provisional email address and transmitted to a transmission destination, and a transmission destination email of a reception email addressed to the provisional email address. Provided is an electronic mail server that reversely converts an address into an original sender mail address and transmits it to a registered user.

For this reason, the electronic mail server includes provisional mail address generation means for generating a provisional mail address different from the transmission source mail address when receiving a transmission mail from a registered user, the transmission source mail address, and the provisional mail address. An e-mail address conversion unit that mutually converts the e-mail address, an expiration date specifying unit that specifies an expiration date of the provisional email address, and an expiration date determination unit that determines whether the provisional email address is within the expiration date or the expiration date. When the e-mail addressed to the temporary e-mail address within the deadline is received from the e-mail address, the e-mail address conversion means identifies the sender e-mail address corresponding to the temporary e-mail address, and sets the e-mail destination e-mail address as the temporary e-mail. Replacing the address with the sender email address and sending the email It is sent to an e-mail address.

In addition, when an e-mail addressed to an expired provisional e-mail address is received from a third party, even if the e-mail address can be specified from the table means, the e-mail is discarded and transmitted to the e-mail address do not do.

  In addition, when the provisional email address expires, the association between the sender email address and the provisional email address is deleted from the email address conversion means, and when an email addressed to the provisional email address is received, Discard the email.

  In addition, when an e-mail including information that does not require conversion to a temporary e-mail address is received from a registered user, the e-mail is transmitted as it is to the destination e-mail address without replacing the source e-mail address.

Further, when an e-mail including the time limit information of the provisional e-mail address is received from the registered user, the e-mail address conversion means manages the time limit based on the time limit information for each e-mail.

  According to the present invention, even if the spam mail addressed to the provisional mail address is not registered for reception rejection, the reception is automatically rejected upon expiration, which is very effective as a countermeasure for spam mail. Operation is simple.

Embodiments of the present invention will be described below.
FIG. 1 is a connection configuration diagram including a mail server having a time-limited mail address conversion function according to an embodiment of the present invention.

  As shown in the figure, the mail server 300 of this embodiment is connected to a router / gateway 200 connected to the IP network 100 via a LAN 101 line. An IP device 401 that transmits and receives mail is connected to the LAN 101 line. Furthermore, it is composed of a partner IP device 402 that transmits mail via the IP network 100 and a mail server 403 that controls transmission / reception of mail between the IP device 402.

In order for the IP device 401 to send a mail to the IP device 402 connected to the IP network 100, the mail is sent from the IP device 401 to the IP device 402 to the mail server 300. The mail server 300 that has received the mail transmits the mail to the mail server 403 connected to the IP network 100 via the router / gateway 200. The mail server 403 that has received the mail transmits the mail to the IP device 402.

At this time, the transmission source mail address of the mail is the mail address of the IP device 401 user, and the transmission destination is the mail address of the user of the IP device 402. In the mail transmission as described above, since the real mail address of the IP device 401 is directly transmitted to the network to the user of the IP device 402, the mail address is known to a third party, and the user of the IP device 401 When a spam mail is sent from the user of the IP device 402 that is not desired, the user of the IP device 401 has to receive the spam mail.

The present invention transmits the user e-mail address of the IP device 401 as a temporary e-mail address, and the temporary e-mail address is a temporary use e-mail address with a time limit. When the mail is sent to the provisional mail address, the spam mail is actually transmitted to the user of the IP device 401 only within the time limit for temporarily using the provisional mail address. Since all mail addressed to the provisional mail address is discarded after the expiration date, it is effective for preventing unwanted mail.

FIG. 2 is a functional block diagram of the electronic mail server 300 having a time-limited mail address conversion function.
As illustrated, the mail server 300 includes a LAN interface processing unit 301, a mail reception control unit 302, a mail transmission control unit 308, a mail address conversion control unit 303, a provisional mail address generation unit 304, and an expiration date designation. A section 305, a time limit determination section 307, and a provisional mail address storage section 306.

  The LAN interface processing unit 301 receives and transmits IP packets from the LAN network 101. When receiving the IP packet, the LAN interface processing unit 301 delivers the IP packet to the mail reception control unit 302. Further, the IP packet of the mail delivered from the mail transmission control unit 308 is transmitted to the LAN network 101.

  The mail reception control unit 302 checks whether or not the destination mail address is a provisional mail address by looking at the header information of the received mail delivered from the LAN interface processing unit 301, and checks whether or not the source mail address needs to be converted. To do. The check result is notified to the mail address conversion control unit 303.

  Next, an example of a registration method when the user uses the time-limited mail address conversion function will be described with reference to FIG.

  FIG. 3 shows a part of the header information of the mail. The mail header 3020 includes a transmission destination mail address 3022, a transmission source mail address 3023 and a subject 3024.

In the case of a mail transmitted from the user of the IP device 401 to the user of the IP device 402, the transmission destination mail address 3022 is the mail address of the user of the IP device 402, and the transmission source mail address 3023 is the IP device 401. User's email address.

In the header information 3020, the subject 3024 describes processing conditions processed by the mail server 300, such as whether or not the sender mail address needs to be converted to a temporary mail address and the time limit when conversion is necessary. If <on, 24>, <off, 00>, <on, FF>, or <on, 00> is described in the subject 3024, the mail server 300 sets the user of the mail including the header information 3020 as a time limit. Judged as a message for using the mail address conversion function, and performs processing corresponding to each message.

If <on, 24>, the mail server 300 determines that “on” needs to be converted into a provisional mail address, and “24” determines that the validity period of the provisional mail is 24 hours.

If it is <off, 00>, it is determined that “off” does not require conversion to a temporary mail address. Here, “00” is described in the present embodiment. However, in the case of “off”, the process does not change even if the numerical value is another value.

If it is <on, FF>, it is determined that the provisional mail address has no time limit and will be used for a long time. Although not shown here, in the case of <on, 00>, “00” means that the expiration date is determined to be 0 hours, meaning that no reply mail from the other party is received.

Next, processing of the e-mail address conversion function with a time limit will be described with reference to FIGS.

FIG. 4 shows the contents of the mail address conversion table 3060 stored in the temporary mail address storage unit 306. This is a table for storing a real mail address 3061, a provisional mail address 3062, a temporary mail address 3062, and an effective time 3063 of the transmission source for each mail transmitted from the IP device 401.

A record 3064 indicates a table for converting the transmission source mail address of the transmission mail from the IP device 401 to the IP device 402 into a temporary mail address. The transmission source mail address before conversion is stored in the real address 3061, and the temporary address 3062 is stored in the temporary address 3062. Stores the converted provisional email address. An effective time 3063 indicates the expiration date of the provisional mail address. For example, “24” is stored.

A record 3065 indicates a case where conversion to a provisional mail address is unnecessary and conversion is not performed, and the transmission source mail address is stored in both the real address 3061 and the provisional address 3062. In this case, the valid time 3063 is described as “AA”, for example, indicating that it has not been converted into a temporary address.

A record 3066 is converted into a provisional mail address and indicates a case where the valid time is infinite. The addresses before and after conversion similar to the record 3064 are stored in the real address 3061 and the provisional address 3062, respectively. For example, “FF” is stored in 3063.

When the mail reception control unit 302 receives a mail from the IP device 401 or the IP device 402, the transmission destination mail address 3022 in the mail header information 3020 delivered from the LAN interface unit 301 is stored in the temporary mail address storage unit 306. It is checked whether it matches the provisional mail address 3062 of the address conversion table 3060 that has been sent, and the mail address conversion unit 303 is notified.

Further, the mail reception control unit 302 checks the subject 3024 of the mail header information 3020 and determines whether or not to convert the mail address to a provisional mail address. The condition for determination is determined by either “on” or “off”. The case of “on” is a case of conversion, and the case of “off” is a case of no conversion.

The e-mail address conversion control unit 303 is notified of e-mail expiration date information described in the subject 3024, as well as information on whether or not to convert.

  The mail address conversion control unit 303 follows whether the mail is addressed to the temporary mail address notified from the mail reception control unit 302. If not, the mail address conversion control unit 303 further determines whether the mail conversion is notified from the mail reception control unit 302. The information is checked, and if conversion is necessary, the provisional mail address generation unit 304 is notified to request generation of a provisional mail address.

When conversion is not required, the provisional mail address generation unit 304 is notified, but the provisional mail address generation is not requested. In both cases where conversion is necessary and unnecessary, the transmission source mail address of the mail is transferred from the mail address conversion control unit 303 to the provisional mail address generation unit 304.

Next, when the provisional email address generated by the provisional email address generation unit 304 is delivered, the email address conversion control unit 303 replaces the sender email address of the email with the provisional email address and sends the email to the email transmission control unit 308. Instruct to send.

Further, the mail address conversion control unit 303 notifies the expiration date specifying unit 305 of the email expiration date information notified from the email reception control device 302. Further, when the expiration date determination unit 307 notifies that the expiration date has passed, the received mail is discarded.

  When there is a request for generating a mail address, the provisional mail address generation unit 304 generates a random mail address from alphanumeric characters, notifies the generated provisional mail address to the mail address conversion control unit, and the source mail address And the generated temporary mail address are registered as the real address 3061 and the temporary address 3062 in the address conversion table 3060 of the temporary mail address storage unit 306, respectively.

At this time, when an instruction not requiring conversion to a temporary mail address is received, the sender mail address is registered and stored as the temporary address in the address conversion table 3060. Therefore, the same address is registered as the real address 3061 and the temporary address 3062 in the address conversion table 3060.

  The expiration date designation unit 305 stores the expiration date of the provisional email address notified from the email address conversion control unit 303 in the validity time 3063 of the address conversion table 3060 in the provisional email address storage unit 306.

  At this time, if the expiration date notified from the email address conversion control unit 303 is “00”, “AA” is stored in the validity time 3063 column, indicating that the email does not have a provisional email address. Further, when the expiration date is “FF”, “FF” is written as it is in the effective time 3063 column to indicate that the provisional mail address is infinite.

  Since this effective time 3063 column is displayed in units of time in this embodiment, it is subtracted by one unit by a periodic job every hour, and when the value in the effective time 3063 column becomes “0”, it is effective. Indicates that it has expired and is not subtracted thereafter.

  The deadline determination unit 307 checks the mail address conversion table 3060 stored in the temporary mail address storage unit 306 and determines whether the received mail addressed to the temporary mail address is within the valid period. Further, when the value of the valid time 3063 is “0”, it is determined that the valid time has passed, and the mail address conversion control unit 303 is notified that the valid time has passed, and the provisional mail address storage unit 306. Deletes the record corresponding to the provisional mail address from the mail address conversion table 3060 stored in.

  The mail transmission control unit 308 transmits the mail delivered from the mail address conversion control unit 303 to the LAN network 101 via the LAN interface processing unit 301.

  FIG. 5 is a flowchart for explaining the operation of the e-mail server 300 having a time-limited e-mail address conversion function.

The mail reception control unit 302 checks whether the mail received via the LAN interface processing unit 301 is a mail addressed to the temporary mail address, and notifies the mail address conversion control unit 303 of the check result. For checking, the mail reception control unit 302 searches the temporary address 3062 in the address conversion table 3060 of the temporary mail address storage unit 306, and determines whether there is an address that matches the transmission destination mail address of the received mail (S501).

If it is not a mail addressed to the temporary mail address (No in S501), the mail address conversion control unit 303 checks the mail header 3020 (S502), and determines whether or not to convert the mail address of the mail to the temporary mail address. Determine whether. If conversion to a provisional mail address is necessary (Yes in S503), the provisional mail address generation unit 304 is notified of the transmission source mail address and a request for generation of a provisional mail address is made.

When the provisional email address generation unit 304 generates a provisional email address according to the request (S504), the provisional email address is notified to the email conversion control unit, and the source email address and the provisional email address are stored in the provisional email address storage unit 306. Are registered as the real address 3061 and the temporary address 3062 of the address conversion table 3060 (S505).

Even when conversion to a provisional email address is unnecessary (No in S503), the email address conversion control unit 303 notifies the provisional email address generation unit 304 of the transmission source email address, but the generation of the provisional email address is requested. No (No in S503).

The temporary mail address generation unit 304 does not generate a temporary mail address, but only registers the address conversion table 3060 in the temporary mail address storage unit 306. At this time, the sender email address is registered in the real address 3061 of the address conversion table 3060, and the same sender email address is also registered in the temporary address 3062 (S505).

However, although not explicitly shown in the flowchart, when registration is already performed for the same source address without conversion, duplicate registration is not performed.

The email address conversion control unit 303 notifies the expiration date designating unit 305 of information on the expiration date of the temporary email address described in the email header 3020. The expiration date designation unit 305 confirms whether or not the expiration date has been set. If there is an expiration date (Yes in S506), the expiration date designation unit 305 validates the email address conversion table 3060 that stores the expiration date in the provisional email address storage unit 305. The registration is saved at time 3063 (S507).

In this embodiment, the expiration date is specified by two digits in the time unit, but may be in seconds, minutes, days, weeks, or the like, and the number is not limited to two digits. Further, as described above, when <off, 00> is specified in the subject 3024, “AA” is registered in the effective time 3063, and “FF” is specified when <on, FF> is specified in the subject 3024. sign up.
Other than the above, when there is no expiration date (No in S506), registration in the provisional mail address conversion table is not performed.

When the generated provisional email address is notified, the email address conversion control unit 303 replaces the transmission source email address with the provisional email address and delivers the email to the email transmission control unit 308. The email transmission control unit 308 The mail is transmitted (S508).

  If the received mail is a mail addressed to the temporary mail address (Yes in S501), the mail address conversion control unit 303 requests the expiration date determination unit 307 to determine the expiration date, and the expiration date determination unit 307 sends the request to the temporary email address storage unit 306. Based on the valid time 3063 of the stored mail address conversion table, it is confirmed whether it is within the valid period.

If it is within the validity period (Yes in S509), the provisional email address is used as a key, the email address conversion table stored in the provisional email address storage unit 306 is searched, and the actual address corresponding to the provisional email address is read. The destination mail address is converted from the temporary mail address to the real mail address (S510).

The mail conversion control unit 303 delivers the mail converted to the real mail address to the mail transmission control unit 308, and the mail transmission control unit 308 transmits the mail to the LAN network 101 via the LAN interface processing unit 301 ( S511). Since the real mail address is the registered user's mail address, the received mail is sent to the registered user intended by the sender.

If the received mail is outside the expiration date, that is, if the valid time 3063 is “0” (No in S509), the mail address conversion control unit 303 discards the received mail (S512), and the prayer determination unit 307 receives the provisional mail address storage unit. The record corresponding to the provisional mail address is deleted from the mail address conversion table stored in 306 (S513).

As described above, the method for determining whether to convert the source mail address according to the information of the subject 3024 of the mail header 3020 and whether to specify the expiration date has been described as an explanation of the present invention. It is possible to use a method that can be set in advance in this mail server, or a method that can be set at any time as required, and even if it is via email, the information described in the mail text instead of the header The method of specifying by can also be considered.

In addition, it has been explained that it is necessary to generate a provisional mail address for each outgoing mail, and a temporary mail address is generated each time it is necessary. If there is an e-mail addressed to the same destination address and the temporary e-mail address generated for the e-mail is within the valid time, the generated temporary e-mail address is not generated without generating a new temporary e-mail address. A method to use is also conceivable. At this time, for the expiration date, the expiration date specified in the new mail is registered in the expiration time 3063.

Connection configuration diagram Functional block diagram Part of email header information Address translation table flowchart

Explanation of symbols

100 IP network 101 Local area network (LAN)
200 router / gateway 300 mail server 301 having address conversion function LAN interface unit 302 mail reception control unit 303 mail address conversion unit 304 provisional address generation unit 305 expiration date designation unit 306 provisional email address storage unit 307 expiration date determination unit 308 email transmission control Unit 401 IP device 402 IP device 403 Mail server 3020 Mail header 3022 Destination mail address 3023 Source mail address 3024 Subject 3060 Address conversion table 3061 Real address 3062 Temporary address 3063 Valid time 3064 Record 1
3065 record 2
3066 record 3

Claims (2)

Provisional email address generating means for generating a provisional email address different from the sender email address of the email when receiving a transmission email from a registered user;
Mail address conversion means for mutually converting the sender mail address and the provisional mail address generated by the provisional mail address generation means;
An expiration date specifying means for specifying an expiration date of the provisional email address;
An e-mail server having an address conversion function with a time limit, characterized in that it has time limit determining means for determining whether or not the provisional mail address is within an expiration date.
The e-mail server according to claim 1,
The e-mail server having a time-limited address conversion function, wherein the expiration date designating unit designates an expiration date of the provisional mail address for each mail.