KR100486905B1 - System and method for preventing spam mail - Google Patents

Abstract

The anti-spam system and method are for redistributing the benefits of sending e-mail and preventing the receipt of unnecessary spam. According to the present invention, a list of senders is registered in advance, and when an e-mail is received from an unregistered sender, the computer can not identify the person and can identify only a person (receiving problem) to the sender and correct the problem. Only sender can receive e-mail. In addition, certain senders who benefit from the commercial use of e-mails may purchase e-mails from the electronic post office to allow e-mails to be received only if they contain e-mails. Email stamps are classified into various categories, such as adult content, depending on the contents of the mail. Depending on the mail recipient's profile, email stamps with specific email stamps can be accepted. Therefore, the present invention can prevent the receipt of a large number of mechanically distributed spam mails by transmitting a problem that only a person can recognize and answer the unregistered email senders, and the unregistered mail senders can Profit generated from purchases is distributed to mail receivers and mail server operators to encourage the use of e-mail and to redistribute profits. In addition, it is possible to prevent the adult advertisement mail attached with the electronic stamp classified as adult to be received in the minor email.

Description

System and method for preventing spam mail}

The present invention relates to an anti-spam system and a method thereof, and more specifically, to allow only a mail of a sender who sends a correct answer by sending a mailing problem to a mail sender who is not pre-registered or to which an e-mail is not attached. In addition, the present invention relates to an anti-spam system and a method for allowing an e-mail to which an e-mail is attached according to a recipient's profile to prevent damage caused by spam mail.

In general, an electronic message sent by a sender to a recipient who has nothing to do with it is called spam, and it is called junk mail because it is nothing but garbage.

Many domestic e-mail service providers are suffering from the heavy burden caused by such spam mails. In addition, almost all Internet users have received spam. As such, the damage caused by a large amount of e-mail (spam mail) was very large, and a recent survey result of the Ministry of Information and Communication revealed.

The current method used to prevent spam is to use unsubscribe and filter functions.

Unsubscribe is to block e-mails from specific senders. The filtering feature blocks emails that contain specific words. E-mail program Outlook Express and all webmail include both of these features. Mail server operators often install and run server programs that block the domains that send a lot of spam.

Another method is to record a specific e-mail address desired by the user and selectively receive only e-mail having the e-mail address.

However, in recent years spammers relay mail to any other ISP or company's mail server without using the direct spam method of sending mail to an unspecified number of users directly through their ISP's mail server. By using the relay spam method to send the mail disguised as a user of the relay server to send an advertising mail to an unspecified number of people to avoid the rejection or filtering function.

Also, because what is considered to be spam for some people may not be for others, it may also be a problem for mail server operators to block certain domains or addresses.

It is almost impossible to block 100% of spam mails so that a daily newspaper surveyed 'anti-spam laws' from domestic Internet experts and said, "There is no idea to expel 100% of spam mails." The key factor is how effectively you can block a significant amount of growing spam.

In general, spammers use a specific spam mailing program to send a batch to an unspecified number of email addresses. Therefore, it is possible to block spam by using spammers' spam mail programs.

In addition, the transmission of the mail in the prior offline takes a lot of expenses in accordance with the manpower and transport and these expenses are to be borne by all the mail sender. However, as the use of e-mail increases, the sender is almost inexpensive compared to the postal transmission used in the past, and there is an advantage in that a lot of mail can be sent at the same time. As the use of e-mail due to spam mail increases, the burden on e-mail processing is increasing and the cost burden is increasing, and this imbalance needs to be resolved. In particular, in the case of using e-mail for commercial purposes, for example, when a credit card company sends a bill to a card user, the card company generates a profit by selecting the recipient to receive an e-mail, but it is the user who generated such a profit. (Mail Recipient) and Recipient-side mail servers, some return to the recipient and recipient-side mail servers for such benefit is necessary. If more users use email through this redistribution of profits, it will bring more profits to the sender, so the problem of redistribution of profits is necessary for all mail senders, mail recipients and recipient mail server operators.

Accordingly, it is an object of the present invention to redistribute the benefits of sending emails and to prevent the receipt of unnecessary spam mails, in order to pre-register a list of senders and to identify computers when mail is received from unregistered senders. The only way to identify a problem (receipt problem) that can be identified is to send it to the sender of the mail, and provide a way to allow e-mail to be sent only to the sender who matches the problem.

It is also an object of the present invention to provide a method for allowing e-mailers to receive e-mails only if they contain e-mails, so that specific senders who benefit from the commercial use of e-mails can purchase e-mails through a private or post office. In providing.

Another object of the present invention is to provide an anti-spam system using the above-described methods.

The anti-spam system of the present invention for achieving the above object, in a system for preventing spam mail, a recipient DB for storing a list of email recipients, and a sender who is not registered in the recipient DB Problem DB for storing the reception problem to determine whether to allow the e-mail, and to enable the sending and receiving of the e-mail, at least one to the sender when the e-mail is received from the sender not registered in the recipient DB And a mail server that transmits the reception permission problem of and allows the final reception of the sender's e-mail upon receiving the correct answer to the reception permission problem sent from the sender.

In accordance with another aspect of the present invention, there is provided a method for preventing spam mail, the method for preventing spam mail, comprising the steps of: (1) registering information of senders who want to allow e-mail reception in a reception permission DB; Determining whether the received e-mail sender satisfies at least one condition among the registration of the receiving permission DB and whether the received e-mail is attached with the preset data (e-mail); and (3) in step (2) If at least one condition is not met, sending at least one receiving problem to the sender's e-mail address; and (4) checking whether the answer to the receiving problem is returned from the sender having the e-mail address for a predetermined time. Determining whether or not the answer to the reception permission problem returned within the predetermined time is the correct answer; and (5) the determination result of step (3) is the correct answer. Only if the sender is allowed to receive emails.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First embodiment

1 is a block diagram of an anti-spam system according to an embodiment of the present invention.

The mail server 11 is a server that allows a user having an account of the mail server 11 to send and receive an email. The received email is pre-registered by the mail receiver 30 or the operator of the mail server 11. Check whether it is from the sender. To this end, the mail receiver 30 and the mail server 11 operator pre-register a list of senders to be accepted in the database. If the result of the check is that the e-mail is from a registered sender, the mail server 11 stores the e-mail in the mail receiver 30's mailbox (13). If the e-mail is from an unregistered sender, the e-mail is allowed to be received by the sender. A problem for determining whether or not (hereinafter, referred to as a "receipt permission problem") is sent to the corresponding mail sender 40.

At this time, the reception permission problem sent to the mail sender 40, the computer can not understand the meaning, it is made of a form that only a person can understand the meaning of the problem and correct the answer. 3A and 3B illustrate an embodiment of a reception permission problem transmitted to an unregistered sender according to the present invention.

Receiving problems that are sent to unregistered mail senders are in the form of a text such as 'How much is 1000 minus the year of the year?', Along with a picture as shown in FIG. 3A. Images and texts mixed with text, songs containing lyrics (♬ Where is the passage of time ♬), along with sounds and texts that transmit the text 'What's the third letter in the song that's flowing?' 3B shows a screen as shown in FIG. 3B on a screen of a mail sender terminal (not shown) and directly transmits the text 'Please click the mouse in alphabetical order (or press the corresponding character with the keyboard)' and a mixed text and event type. Problems can only be solved by a user and the computer can't solve the problem. Agent, can make the images, sounds, events, in the form a mixture of more than one or two. Alternate sounds and pictures can be sent for people with disabilities. Such a reception permission problem may be set in advance in a database, and may be sequentially and randomly extracted and sent out, or may be used by setting the mail server 11 with a problem that is directly produced and selected by the mail receiver 30. In addition, only one receiving permission problem may be sent or a plurality of problems may be sent simultaneously or sequentially. In the case where a plurality of problems are sent, the mail server 11 stores the email of the sender in the recipient's mailbox 13 so that the receiver can check the sender's email.

At this time, since the present invention is to block only the email corresponding to the former by distinguishing whether the computer is sent in large quantities at the same time or a large number of emails sent directly by a specific program such as a spam mail program, the sender 40. The problem is sent to anyone who can easily solve the problem.

Receiving party DB 12 stores information that can distinguish the sender, such as a list of the sender's e-mail address or a list of the IP address of the mail sender (hereinafter referred to as "receiving address book") registered by the user. At this time, the reception address book is divided into a personal address book and a server address book. Lists stored in the personal address book are registered by each mail receiver 30 to receive his or her sender information. Emails from the sender registered in the personal address book are stored in the recipient's mailbox 13 and can be checked by the recipient. Do. The lists stored in the address book for the server are registered sender information registered by the mail server 11 operator. The e-mails from the sender registered in the address book for the server are not registered in the personal address book. It may be forcibly stored in the mailbox 13 of the receiver 30.

Each mail receiver 30 registers senders in his or her personal address book, and mail receivers 30 access their mail servers 11 to their terminals (not shown) and input them daily, mail server 11 ) When a user, that is, the mail receiver 30 sends an email, the email address of the recipient is automatically registered in the personal address book, and in the second method described above, the mail receiver 30 is not registered automatically. After that, the mail receiver 30 may be used to register only when the registration instruction is issued. Moreover, the mail server 11 may transmit a confirmation mail indicating that the registered sender has been registered. On the contrary, if the other mail server is a mail server operated according to the present invention, the mail server 11 may transmit a mail confirming that the mail has been registered. have.

Even if the sender is not registered in the reception address book, the mail server 11 may send the email if the email server 11 includes a specific mark or data contracted with the mail server 11 (hereinafter referred to as 'e-mail'). Allow to be stored in the recipient's inbox 13. As a result, only when the sender is not registered in the reception address book and does not attach the electronic mail stamp, the mail server 11 sends a reception permission problem to the mail sender. These electronic stamps are sold at the private electronic post office 16 on the operator side of the mail server 11 or at the integrated electronic post office 17 authorized by each mail server operator.

The private electronic post office 16 is a mail post office operated by the corresponding mail server 11 alone, and the integrated electronic post office 17 refers to a common post office for using a postage system in which several mail servers are integrated. These electronic post offices 16 and 17 perform not only the release of the electronic postage stamp but also the verification and validation of the electronic postage attached to the mail. When an unregistered mail sender sends a large amount of commercial mail and purchases an e-mail stamp from a private electronic post office (16) or an integrated electronic post office (17) and attaches it to the mail, it is not necessary to answer the e-mail reception problem for each large amount of mail. do. When the mail receiver 30 receives the e-mail attached email, a certain amount of the money can be returned to the receiver 30.

Here, the mail server 11 represents all document transmission servers capable of transmitting electronic documents such as Internet mail, instant messaging system (IMS), short message (SMS), and the like. It is only an embodiment for. Therefore, the client terminal used by the mail receiver 30 and the mail sender 40 in association with the mail server 11 is an electronic document such as a computer, PDA, mobile communication terminal, Internet TV, etc. according to the function of the mail server 11. It is obvious that all terminals capable of transmitting and receiving a message are possible.

2 is a flowchart illustrating a process of preventing spam mail by using a reception permission problem and an electronic stamp according to the present invention.

A mail sender 40 sends an email to an unspecified number of people, including the mail receiver 30 (step 201).

The mail server 11 of the mail receiver 30 that has received the email sent by the mail sender 40 determines whether the mail sender 40 is a sender registered in the receiving address book of the receiving party DB 12. (Step 202). As a method of confirming the mail sender 40, a method of confirming only the sender's email address or a method of confirming the IP address of the mail sender side (mail sender terminal and sender side mail server) together with the email address is used. Since the sender's email address may be falsely entered by the sender, if necessary, find the IP address of the sender's terminal (not shown) and the IP address of the sender's mail server (not shown). The sender's registration is determined by comparing and searching the registered IP address.

As a result of the determination in step 202, if it is not the sender 40 registered in the receiving party DB 12, the mail server 11 checks again whether the electronic mail is attached to the e-mail (step 203). In step 202 and 203, whether the electronic postal mail is attached or not is checked first, whether the receiving party DB 12 is registered or not. In addition, any one of steps 202 and 203 may be omitted, and only one of the steps may be used. The electronic stamp is encrypted so that it cannot be stolen from the outside and is transmitted to the mail server 11.

If the e-mail is not attached to the confirmation result e-mail in step 203, that is, it is not registered in the address book and the e-mail is not attached, the mail server 11 reads "The mail sender 40 is not registered. The mail receiver 30 cannot see the mail sent by the sender 40. In order for the mail receiver 30 to see it, please send a message to the mail sender 40 such as "Please return the correct answer to the attached problem". In the problem DB 14, the reception problem is databased as shown in FIG. 4, and one or more reception permission problems (for example, problem 152) are sequentially or randomly selected and transmitted to the mail sender 40 together with the image of FIG. 3A. (Step 204). In addition, when transmitting a reception permission problem, only one problem may be transmitted or several problems may be transmitted simultaneously or sequentially. When the mail sender 40 uses the Internet mail, it presents a specific URL and allows access to the URL to solve the problem.

If the electronic stamp is attached as a result of checking in step 203, the mail server 11 checks whether the attached electronic stamp is authenticated by the private electronic post office 16 or the authorized integrated electronic post office 17 (step 211). ). If the attached electronic stamp is an authenticated electronic stamp, the mail server 11 finds out the validity of the electronic stamp, its type, and the like through the corresponding electronic post offices 16 and 17 (step 212). The mail server 11 checks the profile 18 set by the e-mail receiver 30 and finally determines whether or not the e-mail is received by the recipient when the e-mail is confirmed as a valid e-mail at the e-mail office 16 or 17. (Step 213). Even if the electronic postage stamp is attached in step 213, the sender 40 notifies the sender 40 that the mail reception is not allowed according to the recipient profile 18 according to the recipient profile 18 (step 210). If it is not a valid electronic postal stamp in step 212, the mail server 11 notifies the sender that the attached electronic postage is invalid, and then deletes the sender's email (step 214).

Email stamps are not one thing, but depend on the content of the outgoing mail. The electronic post office (16, 17) that purchases electronic stamps examines the contents of the mail and purchases electronic mail stamps suitable for the contents. The categories include adult, prizes, membership confirmation, and product purchase confirmation. It can be divided in various ways. For example, a commercial mail with adult e-mail will not be reached if adult mail is disallowed in the recipient profile 18. Through this, even if an e-mail is attached, it is possible to prevent the adult from receiving adult mail.

In addition, if you subscribe to a specific site by entering your own mail, you can receive an e-mail with a 'for membership registration'. This makes it easy to receive e-mails that are notified to users individually without having to put them in the 'Address Receipt Address' each time. This will be described later with reference to FIG. 5.

The mail server 11 checks whether the answer of the problem has been transmitted from the mail sender 40 which has received the reception permission problem (step 205). If the sender 40 of the check result of step 205 did not send an answer, the mail server 11 deletes the received e-mail or moves to a junk mailbox, and if the sender 40 sends the answer, the mail server 11 sends the sender ( Check if the answer sent by 40 is the correct answer (step 206). Here, the confirmation of the correct answer is made by storing the correct answer and comparing it with the received answer. In step 205, even if there is no reply from the mail sender 40 for a predetermined time, the email from the mail sender is deleted. Alternatively, the sender's emails that are not allowed to receive mail can be stored separately in the Junk mailbox so that they can be deleted after a certain time so that the user can check the emails that are not allowed.

If the result of the check in step 206 is a correct answer, the mail sender 40 is notified of the correct answer (step 207), and the e-mail of the sender 40 is stored in the mail receiver 30 in the mailbox 13 to be received. Allow the user to check the mail (step 208). In this case, when a plurality of questions are transmitted, the operation of step 207 is performed only when the answer to all the questions is a correct answer.

If the received answer is not the correct answer, the mail server 11 determines whether the number of incorrect answers received is less than the preset number (step 209). If the incorrect answer number is less than the preset number, the mail server 11 applies the preset number of times again. Repeat the steps 204 to 206 by sending a problem of receiving permission to the mail sender 40, and if the number of incorrect answers is greater than the predetermined number of times, the mail sender is notified that mail reception is not allowed, and then the sender's e-mail is deleted. (Step 210).

In step 202, if the mail sender 40 is a sender registered in the recipient DB 12, or in step 211, if the e-mail attached to the e-mail is a recipient-allowed mail, the flow proceeds to step 208. In the mailbox 13 of the recipient 30 to allow the recipient to check the email.

5 is a flowchart illustrating a main receiving process through an electronic postal stamp for membership.

When the user, that is, the mail receiver 30 registers for a specific website (step 501), the user enters a receivable email address (step 502). When the e-mail address is input, the specific website which has been registered automatically requests the electronic postage stamps from the electronic post offices 16 and 17 (step 503). At this time, the electronic post offices 16 and 17 distribute the electronic stamp for membership to the specific website that requested the electronic stamp (step 504). The mail server of the website side which has distributed the electronic mail stamp for membership registration automatically attaches and sends the electronic mail stamp for membership mail to the member (step 505). The mail server 11 or 15 of the user, namely, the mail receiver 30 recognizes that the mail is attached to the member, and stores the corresponding email in the mailbox 13 of the receiver 30. Allow the recipient to check the email (step 506).

This method can be used in all areas that allow a user to receive mail for a particular website. For example, in an online shopping mall, a user may purchase a product and send a mail to the user about the result thereof.

When the above-described method is applied, a sender who sends an unregistered spam mail receives a receiving permission problem. In this case, when a batch of spam mails are sent to an unspecified number through a computer, the sender who sends the spam mail is not able to solve the problem. Since the correct answer cannot be sent, the mail recipient does not have to receive unnecessary spam. If the mail sender wants to send an e-mail to the mail receiver 30, he or she needs to purchase an electronic postage, and thus the mail server 11 operator and the mail receiver 30 can obtain a profit.

Second embodiment

6 is a block diagram of an anti-spam system according to another embodiment of the present invention. The system shown in Fig. 6 is configured in the same way as the system shown in Fig. 1, and separately constitutes a reception permission problem server 21 which manages and operates only reception permission problems. As shown in FIG. 6, when the reception problem server 21 is constructed and operated separately from the mail server 15, one reception problem server 21 may be used in correspondence with a plurality of different mail servers.

The mail server 15 checks the registration of the received e-mail sender, and a signal for requesting a reception permission problem when the sender is an unregistered sender in the receiver allower DB 12 (hereinafter, referred to as a "problem request signal"). Send to the reception permission problem server 21.

The reception permission problem server 21 manages and controls the problem DB 14. When the problem request signal is received from the mail server 15, the reception permission problem server 21 sequentially or randomly receives the reception permission problem stored in the problem DB 14 and the correct answer of the problem. Select to assign to the mail server (15).

The mail server 15 transmits the reception permission problem assigned from the reception permission problem server 21 to the sender 40, and stores the correct answer separately. When the mail server 15 receives an answer from the corresponding mail sender 40, the mail server 15 checks whether the received answer is the correct answer by comparing it with the correct answer. The other processes are the same as in the above-described first embodiment.

Third embodiment

The present embodiment is configured in the same manner as the system configuration of the second embodiment shown in FIG. 6, in which the reception problem server 21 transmits a reception problem directly to the sender and receives a reply from the sender to allow the sender to accept. Determine.

The mail server 15 checks the registration of the received e-mail sender and transmits the e-mail address of the sender to the reception permission problem server 21 together with the result.

The reception problem server 21 receives a signal indicating that an e-mail of an unregistered sender has been received from the mail server 15 and the email address of the sender. The reception problem stored in the problem DB 14 is directly transmitted to the sender 40. Send and receive the answer directly from the sender 40 to check whether the correct answer. In step 206 of FIG. 2, when the answer from the sender 40 is a correct answer, the reception permission problem server 21 notifies the mail server 15 and the sender that the answer is correct. While receiving the transmission problem to the sender 40 determines whether the reception. If the sender fails to meet the correct answer for a certain number of times, the fact is sent to the mail server 15.

The mail server 15 notifies the sender of rejection if it receives a signal from the reception permission problem server 21 that it has not received a reply from the sender for a predetermined time or a correct answer for a predetermined number of times. Delete the message or save it to your Junk mailbox.

Other processes are the same as in the first or second embodiment.

Fourth embodiment

Unlike the above-described embodiments, the fourth embodiment relates to an anti-spam system using at least one temporary account other than the main account used by the user. That is, in the present embodiment, unlike one conventional mail server supporting one mail account, one mail server supports a plurality of mail accounts (main account and a plurality of temporary accounts). At this time, the temporary account of the mail account can be created at any time desired by the user and used by registering with a mail server (not shown), and can also be deleted. The mail server (not shown) integrates and manages a plurality of e-mails received by a mail account registered to the same user in a single receiving DB (not shown), so that a user can integrate several mail accounts through one main account. can confirm. Temporary mails with a lot of spam can be deleted at any time, and a mail account can be created at any time according to the purpose of the mail server user.

When you reply in the process of checking the e-mail from this account to the temporary account, the mail server automatically checks which mail came into the account and the reply is made to the corresponding mail account. This allows the user to use the mail server freely without any confusion between the main account and the temporary account.

These temporary accounts can be used for a variety of purposes when writing on the Internet bulletin board. If you create a temporary account when you create a job ad, and the job is closed after a certain period of time, you can easily delete the account.

As described above, the anti-spam system and method of the present invention is a spam mail that is mechanically distributed in large quantities by sending an unregistered e-mail sender a problem that a computer cannot recognize and only a person can recognize and answer. It is possible to prevent the receiving of mails in advance, and by distributing the profits generated by the unregistered mail senders by purchasing the e-mail stamps, the mail receivers and mail server operators can distribute the profits and create redistribution of profits. . In addition, different e-mail stamps, such as adult and membership confirmation, may be used according to the contents of e-mail to search for and determine the profile set by the e-mail recipient without receiving e-mails with e-mail attachments unconditionally. It can be prevented at the source.

1 is a block diagram showing an embodiment of an anti-spam system according to the present invention,

2 is a flowchart illustrating a process of preventing spam mail by using a reception permission problem and an electronic stamp according to the present invention;

3A-3B illustrate an embodiment of a reception permission problem transmitted to an unregistered sender according to the present invention;

4 is a diagram showing a data structure of reception allowance problems stored in a problem DB;

5 is a flowchart illustrating a mail receiving process through an electronic postage stamp for membership;

Figure 6 is a block diagram showing another embodiment of the anti-spam system according to the present invention.

<Description of the symbols for the main parts of the drawings>

11,15: Mail server 12: Recipient DB

13: recipient mailbox 14: problem DB

16,17: Electronic Post Office 18: Recipient Profile

21: Receiving problem server 30: Recipient of mail

40: mail sender

Claims (28)

In the system to prevent spam mail, A recipient DB for storing a list of email recipients; A problem DB for storing reception permission problems for determining whether to allow reception of an e-mail of an unregistered sender in the reception allower DB; And E-mail transmission and reception is possible, and when an e-mail is received from a sender not registered in the recipient DB, the at least one receiving permission problem is transmitted to the sender, and a correct answer to the reception problem sent from the sender is received. Anti-spam system including a mail server that allows the final reception of the sender's email when receiving. In the system to prevent spam mail, A recipient DB for storing a list of email recipients; A problem DB for storing reception permission problems for determining whether to allow reception of an e-mail of an unregistered sender in the reception allower DB; At least one mail server which enables transmission and reception of an e-mail and transmits a problem request signal to a predetermined place when an e-mail is received from a sender not registered in the receiving user DB; And A reception permission problem server for controlling the problem DB and transmitting the problem request signal from the mail server to at least one reception permission problem and a correct answer stored in the problem DB to the mail server; Include, The mail server transmits at least one reception permission problem received from the reception permission problem server to the sender, and upon receiving the correct answer to the reception permission problem from the sender, a spam mail for the final reception of the sender's e-mail. Prevention system. In the system to prevent spam mail, A recipient DB for storing a list of email recipients; A problem DB for storing reception permission problems for determining whether to allow reception of an e-mail of an unregistered sender in the reception allower DB; At least one mail server that enables transmission and reception of an e-mail and transmits a problem request signal and an e-mail address of the sender to a predetermined place when an e-mail is received from an unregistered sender in the receiving user DB; And Controlling the problem DB, and when receiving a problem request signal and an e-mail address from the mail server, transmits at least one reception permission problem stored in the problem DB to the sender's e-mail address, and transmits the problem to the reception permission problem from the sender. It includes a reception permission problem server for transmitting the correct answer to the mail server, The mail server is a spam mail prevention system that allows the final reception of the sender's e-mail when the correct answer received from the receiving problem problem server. The anti-spam mail system according to any one of claims 1 to 3, further comprising an electronic post office for releasing an e-mail stamp corresponding to the contents of the e-mail to be sent and allowing the e-mail sender to purchase and attach it to the e-mail. The spam mail according to claim 4, wherein the mail server permits the reception of the e-mail regardless of whether the e-mail is attached to the received e-mail regardless of whether the e-mail is attached to the received e-mail. Prevention system. The system of claim 4, wherein the electronic post office checks the authenticity, validity, and type of the electronic stamp attached to the received email. 7. The method of claim 6, wherein the mail server determines whether the mail contents can be received by the recipient by searching the profile set by the email recipient when the electronic postage attached to the received email is confirmed as a valid electronic postage at the electronic post office. To allow reception, and if it is confirmed as an invalid e-mail, an anti-spam system characterized by notifying the sender that the e-mail is not valid. The system of claim 7, wherein the mail server attaches an adult electronic postage stamp to the received e-mail and disallows receiving the e-mail when the e-mail recipient is a minor. 5. The method of claim 4, wherein the electronic post office attaches an e-mail to the user who has allowed e-mail to the e-mail to confirm that the e-mail is from the e-mail to be accepted. Anti-spam system, characterized in that distributed. 10. The method of claim 9, wherein the electronic post office distributes a member-specific electronic stamp on a specific website so that the mail server of the website is attached to the member subscriber, and attaches an electronic stamp to prove that it is a member-only mail. An anti-spam system characterized by the above. The mail server according to claim 1 or 2, wherein if the mail server does not receive a reply from the sender for a predetermined time or does not receive the correct answer for a predetermined number of times, the mail server notifies the sender of rejection and deletes the mail or deletes the junk ( JUNK) Anti-spam system, characterized in that stored separately in the mailbox. The sender of claim 3, wherein the mail server notifies the sender of rejection when receiving a signal from the sender problem problem server not receiving a reply from the sender for a predetermined time or receiving a correct answer for a predetermined number of times. And delete the e-mail or store it separately in the Junk (JUNK) mailbox. The system of claim 11, wherein the mail server transmits a reception permission problem corresponding to the language of the sender using language information set in the sender's email. The system of claim 12, wherein the mail server transmits a problem corresponding to the language of the sender using the language information set in the sender's email. The method according to any one of claims 1 to 3, wherein the recipient DB is A server list for storing information of mail senders allowed by the mail server operator; And An anti-spam system, characterized in that each mail recipient has a personal list that stores information of the mail senders who are allowed to receive. The system of claim 15, wherein the receiving party DB stores an email address of a registered sender or an IP address of a sender. The spam mail of claim 16, wherein the mail server determines whether the sender is registered by comparing at least one of the sender's e-mail address and the sender's IP address with a value previously stored in the receiving user DB. Prevention system. 16. The system of claim 15, wherein the mail server can store emails from senders registered in the list for the server in a mailbox of each mail receiver without permission of each mail receiver. The system of claim 15, wherein the mail server automatically registers the email information in the reception permission DB or asks for registration when sending an email to an email address not registered in the reception permission DB. delete delete In a method for preventing spam mail, (1) registering information of senders who want to allow e-mail reception in advance in a reception permission DB; (2) determining whether a received e-mail sender satisfies at least one condition among whether the receiving permission DB is registered and whether the received e-mail is attached with predetermined data (electronic stamp); (3) if at least one condition is not satisfied in step (2), sending at least one receiving permission problem to the sender's email address; (4) checking whether the answer to the reception permission problem is returned from the sender having the e-mail address for a predetermined time, and determining whether the answer to the reception permission problem returned within the predetermined time is the correct answer; And (5) A method for preventing spam mail, comprising the step of allowing the sender to receive an e-mail sent only if the answer returned is the correct answer. 23. The method of claim 22, wherein the reception problem is a form in which a computer cannot recognize the problem and can only be checked by a person who has confirmed the reception permission problem. 23. The method of claim 22, wherein if the answer to the reception problem from the sender having the e-mail address is not returned for the predetermined time, the e-mail of the sender is deleted or stored in a junk mail box. . The method of claim 22, wherein the receiving permission problem transmitted to the sender in the step (2) is in a language corresponding to the language set in the sender's e-mail. 23. The anti-spam mail prevention method according to claim 22, wherein the registration of the allowable DB is determined by comparing at least one of the received e-mail sender's e-mail address and the sender's IP address with a pre-registered value in the allowable DB. Way. The method of claim 22, wherein step (3) (3a) if the electronic stamp is attached as a result of the determination of step (2), verifying and authenticating the authenticity of the attached electronic stamp; (3b) checking the validity of the electronic stamp certified in step (3a); (3c) if the electronic stamp is valid as a result of the checking in step (3b), determining whether the mail is accepted by the recipient, and if the electronic stamp is not valid, informing the sender that the electronic stamp is invalid; And (3d) a method for preventing spam mail, comprising the step of allowing the reception only when the mail is accepted by the receiver as a result of the determination of step (3c). 28. The method of claim 27, wherein the step (3c) determines whether the e-mail recipient is allowed to receive by searching the profile of the e-mail recipient when the type of the electronic postage stamp is adult.