Email is one of the most important applications on the Internet, which provides a very convenient and fast communication. However, many netizens have experience in the failure of sending emails. By detailed discussion on how to make a detailed discussion on the cause of E -Mail transceivers, let me talk about how to improve the success rate of E-MAIL transmission and reception. First, the general process of E-mail, in general, e-mail's letter is divided into two types: one is a letter from the SMTP sender service provider provided by the ISP or free email service provider; another It is the way to send an email through this unit to establish a S MTP sender server. 1. The transceiver process of sending a letter through the mail letter server. During this letter, the sender is first sent to the SMTP sender server through the computer. If the message received by the sender is legal, the sending server passes the newspaper through a "storage forwarding" technology. The message is queued on the server. When the wheel arrives in the mail, send the message to the other party's recipient (MX mail switching server), then forward it to the POP3 server (many servers) The system's receiving server and POP3 server are the same server), and finally take an email from the P OP3 server to client software on the computer. 2. The process of sending an email directly through this unit. Unlike the above-described transmission process, some software provides the functionality directly to send an email to the recipient server. In fact, use the machine computer to establish an SMTP sender server, which acts as the function of the sender server, bypass I sp or free email supplied SMTP sender. Therefore, the unit actually acts as both the sender computer, but also serves as a letter from the letter, but it is similar to the above process, but reduces the network transmission process between the sender and the sender server and the queue waiting time. Second, the reason for the failure of email is in the above-mentioned letter, as long as there is a problem with a link, it will cause the E-MAIL to send and receive, and therefore, there are main factors in the email transceiver: 1, not properly configured the client. Software account, server properties, etc. Correctly configure the mailbox account for client software, the server properties of sending and receiving mail are the key to successfully transmitting E-mail. The main two servers are required here, that is, the SMTP server and P OP3 servers and accounts and passwords. SMTP Server: You can send the address of the server to send mail, and your message will be sent out by this server. Such as: xf.hb.cninfo.net. You can also write an IP address format, such as: 61.136.152.3. POP3 Server: Save the outside world to send you. You download these messages to your PC through mail client software, for example: Outlook Express to your PC and processes these messages. If SMTP and POP3 are the same host, both are the same, as: xf.hb.cninfo.net. Similarly, some free mailboxes are usually plus "P OP.", Such as Pop.163.com. POP3 and SMTP servers generally have the following filings: 1) SMTP.XXXX.XXX pop.xxxx.xxx 2) xxxx.xxx xxxx.xxx 3) SMTP.XXX.XXX POP3.XXXX.XXX account: actually POP3 Server account. You receive your email from the POP3 server through this account and the corresponding password. Such as: Your mailbox is t010405@xf.hb.cninfo .NET, then your account is "T010405" before @.
Some free email accounts need to fill in the full name, not just the part of @, if you confirm that your password is correct, you can't verify password, usually this reason. Password: Your account password. Email can only be sent correctly if you fill in this information correctly. Primary users are most likely to make the above errors. 2. The recipient's email address is filled in an error. It is important to ensure that email can be properly sent and received by the recipient, accurately fill in the mailbox address. Email cannot be sent to normal or recipients can't receive emails, often the incorrect mailbox address is incorrect. At present, because everyone is registered with the mailbox, it is often not easy to register to the good account name, so everyone has to mix using letters and numbers and some special characters, and this is often easier to cause a copy of the other party's mailbox address. For example: English lowercase letters "L" and Arabic numbers "1", English lowercase letters "O" and Arab numbers "0", underline "_" and even characters "-" These characters are extremely similar, in the copy recipient email address In particular, you should pay attention to it. The recipient email address is completed, and it is divided into two situations: 1) Email address account error: that is, the recipient mailbox @ Fill in the error. It is divided into two situations here. The first case is that the address account is misused. The address account is written into an email address, such as: sending a trafficker xiangkai68@sina.com hopes to send the letter to zxk 71@21cn.com, the address is mistaken Fill in ZXK717@21cn.com (there is an email address), the message is not sent to the hope of the hoped mailbox, and of course the recipient can't receive the email. Another situation is that the address account is completed into other mailbox addresses, such as: The recipient address is: z xk712871@21cn.com (this mailbox address does not exist), then in the process of mail server, It is generally not prompted to send an error, but a prompt to send success (generally transmit email between the same mailbox in the domain name, the sender is determined whether the mailbox address is correct and gives an error message). Because as long as the message can be transmitted correctly to the sender server, O UtLook Express, Foxmail and other mail client software will give a prompt to send success. In the next few minutes, you will find that your mailbox will return the email you sent and inform you that the recipient's email address is illegal or does not exist. So if you don't check your inbox in time, I thought that the other party had received an email? There is also a situation, if there is no corresponding email address on the receiving server, some of the receiving servers will "smart", send them to the right email address, such as: Send to J ohn@myorg.com The mail is sent to johm@myorg.com, but it is generally notified to send the information. When the client software that uses this machine directly sends an email, since it is in a way that is directly connected to the receiving server, it is generally notified that the recipient's mailbox address does not exist during the transmission process. However, when the M X Mail Exchange Server is not the same server, as long as the message is sent to the MX mail swap server, it will be notified to send success, but soon you can receive the returning notification. 2) Host address domain name Error: ie the part of the recipient's mailbox @ fill in the error. In this case, during the transmission process, the message cannot be found at all, if the corresponding host (server) cannot be found after the domain name is analyzed. Therefore, when filling in the recipient email address, it should be very careful. For friends who are often contacted, they can add them to the address thin, and they are directly selected when sending letters.
It is best to use a reply to avoid the email address. For an unspeakable mailbox address, it is best to use the check mail address class software before checking. 3, the sender server has failed. For the sender server, the failure is inevitable. Because many of the network busy, hacker invasion, it may make it temporarily possible to have a temporary failure and cannot be accessed. In this case, it is certainly unable to send email, and we only wait for the sender to return to normal. Resend. The mail server system upgrade can also result in changes in the sender I P address, which cause the original sender server that cannot be accessed (some users fill in the IP address form when filling in the client software). If you have multiple mailbox account, you can also change a message server. The best way is of course software that can provide emails that can provide emails directly (for example: a dvanced direct remailer2.17, hereinafter referred to as ADR, download address: http://www.mailutilities.com/adr/adr.zip) To send, this can bypass the sender server and send an email to the receiving server. In addition, the sender server is best to fill in the form of domain names, do not fill in the I P address form, as this avoids the change of the message server IP address caused by mail system upgrade, so that the email cannot be sent normally. 4, the receiving server has failed. Similarly, not only the sending server is prone to failure, the receiving server, the POP3 server also faults. Generally speaking, when the mail is temporarily fails, the mail is not lost in some cases, because when the receiving server fails, the sender is not allowed to send the message to the specified receiving server, send a letter server It will be resended at the specified time interval, for example, it is sent once after 3 0 minutes. If it still does not send success, it will be sent once after 60 minutes, and so as so as to transmit it until it is successful. In general, when the receiving server fails, the system administrator will restore other restores in a short period of time. If you cannot send successfully within the specified time, for example: 4 8 hours, the message will be refunded to the sender and the reason for the mail cannot be successfully sent. In fact, during this time, you can't immediately know that the clutch server has problems. So for important letters, if you send the software sent to the email directly, you can know if the receiving server is normal, so that other communication methods can be taken, such as fax, etc. to contact your friends. . If there is a problem with the recipient server, there is no way to send the trafficker, we only have the prayer recipient server to return to normal as soon as possible. 5, the domain name resolution server has failed. General users When sending an email with a mail server, you need to parse the domain name address of the sender server, and you need to resolve the domain name address of the recipient server when you receive it. Therefore, when the domain name resolution server fails, the user must not connect to the server, the user cannot connect to the server, and the user cannot be connected to the server. If the user fills in the server address of the sender message into the I P address, you can avoid the domain name resolution server failure and cannot properly send an email. Also use this machine to send email to send email, if the domain name solution server fails, or the suffix domain name of the message address is conflict with the resolution of the domain name server, the domain name address of the other party's recipient server is also unable to resolve. We only replace another domain resolution server.
Therefore, we must fill in the main control DNS and auxiliary DNS correctly in the W Indows network TCP / IP settings, which can call another auxiliary DNS when a domain name resolver server occurs. In addition, China Telecom 169 network is not legal internationally, then 169 network domain names use 163 international online domain name resolution server to resolve the domain name cannot be resolved or parsed, resulting in failure or sending to incorrect In the mailbox. Some domain name parsing the server may have a problem with the resolution range, and cannot resolve the extremely special address, so the message cannot be sent to some special mailboxes. 6. In the process of network connection instability, a stable and fast network connection is also an important factor that guarantees the normal transmission of mail. If there is a disconnection, a strong line electromagnetic interference occurs during the transmission of email, and the natural recipient cannot receive normal emails. At this time we only resend the email. In particular, during the sending big mail, the quality requirements for the network connection are higher. It is therefore recommended that everyone should establish a stable and fast I NTERNET connection before sending an email, and select a fast and stable connection from the local ISP (163, 169, 263, 167, etc.). It is best to compress the attachment before sending, to reduce the size of the mail, of course, the cat should choose a little, and in the process of sending an email, it is best not to make other browsing operations, so as to avoid occupying bandwidth, extend the transmission time, increase Great creation of errors. 7. The email property exceeds the restriction of the sender server. In order to make full use of network resources, improve the response speed and efficiency of the mail sending the user. The SMTP Sending Server limits the size, connection number of the user mail, and the server will refuse to send when the SMTP server is exceeded. In general, the message server has the following restrictions on the message: limit the mail size: whether the free email or the SMTP server provided by the ISP, the size of the sending message is limited, generally less than 2M (including attachment), and actual We can only send 1 .5M or so, because you need to encode the message before sending an email, it will cause the email size between 5% to 20%. And if you can send more messages, please refer to the information of the relevant S MTP server. When the client mail program is attempting to send a message greater than this restricted message to the SMTP server, the unprecedented report or send an error report will then return the message to the client. Limit the number of messages for each connection: Restricting the number of messages that can be sent in a single connection, which exceeds this restriction will be denied. Restrict the number of recipients for each message: Limit the upper limit of the number of recipients per email, and the message exceeds the upper limit will return the sender. When the email exceeds the above limit, we can send an email several times, or divide a larger message into several parts, send a large number of emails, so that each letter is shorter, each time The number is also small, and it can also greatly reduce the probability of error. Of course, if we use this unit to send email software, for example: A DR to send mail, it will generally break through these restrictions, and you can easily send a big email. 8. The recipient's mailbox space is full on the recipient server; the email size exceeds the restrictions of the receiving server. If the recipient is more email, the recipient will not pay for some reason for a long time, as well as the interference of spam, and will often cause the mailbox space, and of course, it will not be able to receive a new email. This is also the same as the attack of the mailbox bomb. Some acceptance server mailbox defaults to reserve backups on the server after the reception method, often causes the mailbox space to be smaller, and causing the reason that the new mail cannot be charged.
Therefore, everyone must develop regular access to mailboxes and cleaning mailbox habits, and set the garbage filtering function of the mailbox to reduce spam interference. In addition, the received mail is too large, and the limitations of the receiving server are not allowed to receive an important reason for the mail. For this case, everyone only applies a large-capacity mailbox space, such as a mailbox of 5 0 ~ 100M, and a large-capacity mailbox is widely restricted to the reception and transmission of large mail. Similarly, the receiving server also has a limit on the size of the received mail, for example: a 5M mailbox allows the maximum single message to be received to 2 m, and does not receive mail normally when it exceeds its limit. 9. The receiving server is set to have a "blacklist" to prevent spammer from sending spam, restricting messages to some mailboxes and a certain IP address range. Some receiving servers have a very strong protection of hosts that send spam, so many legitimate emails cannot be sent to the recipient mailbox, and the address of these spa mmer hosts is registered as "black" List, the receiving server will refuse to charge and send an email to the address or domain name. So you should be confident that your E-mail address or domain name address is not marked as spammer, otherwise, many receiving servers will reject your connection. In this case, you can replace other mailbox S MTP sender servers to send emails, or directly send emails directly, bypass mailboxes or SMTP sending servers listed as a blacklist, it is possible to avoid black List and improve the success rate of sending emails. 10, the recipient mailbox is actively set with garbage filtering, preventing some email from some mailboxes and some emails and a certain IP address. Note: Unlike previous reasons, this is the message filtering feature of the recipient to actively set the mailbox. If the sender mailbox is forbidden to receive users, in most cases, senders can send mail to the receiving server, and do not prompt any errors during the send, but the message is then transferred to another folder, for example:: Directly sent to the spam or deleted, no longer entering the inbox. Therefore, there is no message in the inbox, and it is impossible to charge during the email charge. Nowadays, there are all free email, such as spam filtering, such as HOTMAIL.COM mailbox, we can log in to the mailbox through the web page, will set the mailbox's spam filter level to "high", will not pass Send an email to the hotma il.com mailbox, otherwise it will be filtered out as spam. If the recipient is listed as an object of the rejection, it cannot be sent to the inbox through the mailbox. 11, the receiving server sets a refusal function to the software (mainly group software) that sends an email (mainly the software). Many receiving servers are in order to prevent spam from spreading, there is a monitoring feature on the market, and they are discovered that these messages are sent to the specified mailbox. This is mainly by judging the analysis or other relevant information of the message header, in general, the mail sending tool places information on the message header when encoding the message, such as the X-MAILER information in the email header, mainly It is the mail software used when the mail is sent. The recipient server will judge what the email is sent by this information. If the receiving server is found to be sent with these group issues, it will refuse to receive or filter out, and do not return any prompt information to sender. 12. The receiving server has a refused function on the subject and content of the message.
When sending an email, you must pay attention to the words of the email theme and email content. Many websites have set up common spam to filter spam. If the email topic and email content include: a large, publicity, money For groups, the server will filter out the email, can't send success. Therefore, you should use the text and words that have the suspected text and words that have spam in your mind when writing email themes and content, can also send emails smoothly. 13. Some send trust servers refuse to send messages from non-server messages to reducing the burden and boycotting spam. Most free mailboxes use SMTP server authentication and refusal to send the sender's address non-copy of the server to prevent spam distributors from using this server to send spam. For example, if you have an email zxk@21cn.com on 2 1CN, there is another email xiangkai68@sina.com on Sina, you send an email with the mailbox zxk@21cn.com, and on the SMTP letter server Fill in Sina's SMTP server, namely smtp.sina.com.cn, and fill in the right username and password, you can't send emails normally because of this reason. 14. Some sending servers add SMTP server authentication capabilities, only the server registered users provide the correct username and password to send emails. If you are not a legitimate user registered by this server, you can't provide the correct username and password. It will not be able to send an email using its server, mainly to avoid illegal users to use this server to send a large amount of spam, reduce the interference of the user's mailbox. . Now many earlier versions of email client software, such as F oxmail3.0 does not support this feature, so you should first upgrade your client mail software. 15. Send a letter server or a receiving server refuses to send and receive an anonymous email or an unlamatic email header. In general, whether it is a letter from a letter server or a receiving server, in order to make full use of network resources and prevent hackers, there is a certain spam filtering and firewall feature, which is generally not allowed to send an anonymous email, S MTP server Once, it is discovered that the fields in the mail header are empty or unlaminated, and they will be refused. On the other hand, it is impossible to return an error message to the sender after the email is sent. So before sending, client software and server will first determine this information, only when these mail headers are correct, they can be sent correctly. So now most mail client software must fill in the sender email address correctly when setting or establish a new message, and the general system will automatically take the current account mailbox. If you don't fill it, you generally cannot send it. However, there are now many software that supports anonymous email. Most of the machine directly builds the S MTP server. Directly send emails directly. For the receiving server, this requirement is not strict, and most of the information Under, you can receive anonymous mail, of course, when sending an email to some security levels requires a higher level of receiving server, the recipient server often refuses to send to a given mailbox because the same reason. Therefore, it is important to fill in the mail header information correctly and completely to properly send email. 16. Some receiving servers receive emails from the other mailbox on this domain email address to this domain email address only to receive the mail sent by their own SMTP servers. For example, if you send an email to another mailbox user on 163.com with a 163.com mailbox, you can send it with SMTP.163.com, and if you use other SMTP servers to send, for example: some local i sp If the SMTP server provided without an authentication is sent, the send failed will be prompted.
Similarly, you can't send success with express delivery, which is this reason. This limit is also present, but the sending process does not prompt sending failed, but the next day, it will receive a refused return letter. 17. The receiving server is limited to the number of emails of the email to the same mailbox address in a connection. For this situation, American On-line, domain name aol.com, is not very good at this point, if you are in a short interval, such as one minute, send dozens of letters There may be problems with users who give Aol.com. At this time, the AOL filter will open, think you are sending spam, and kicking your email and does not return any error tips. A OL does not inform you, and you don't know, your IP address will be locked as a blacklist, and will never be received after the letters sent from your email address. AOL receives all emails sent to him, do not send any error prompts, and then eliminate them. For this case, we can use the ADR to send, you can use ADR to send, and use ADR to create a delay list of sending mail, for example, if you send 30 letter to A Ol.com users, You can set an email every three minutes. 18, computer virus or hacker Trojan modify or occupy the port address of the client software receiving and sending an email. Typically, the port address of the SMTP message is 25, and the port address of the receiving server is 110. If it is attacked by a virus or a hacking Trojan, it is possible to change or be occupied by other software, so that the transmission email fails, so when the system originally working properly does not properly send an email normally, it does not prevent Look for this reason this. 19. The "recipient" or "copy" format in the client mail software is incorrect. In Outlook Express, when sending the same letter to multiple recipients, each recipient's mailbox needs to be separated from a semicolon or comma, but can only be separated by a comma in Foxmail, and cannot be separated by a semicolon. Open, otherwise you cannot send an email normally, please have to be clear. Therefore, everyone should first read the relevant documentation of the software when filling out the recipient email address, and carefully check if the format is correct. 20, client mail software itself has insufficient or unregistered. The client software that is emitted now is very much, and there are features, but they have some problems more or less. Therefore, when you choose these mail software, you should try to choose a large company's mature product, and you should also upgrade the update, because the mail server system is always upgraded, so the software should also adapt accordingly. For example: mail super fast mailexpress1.5 (download address: http://jiahuan.zip) Unregistered version, you cannot successfully send 21cn.com mailbox and sina.com mailbox. Tip "Send Success" during the transmission process, but the inbox does not receive the message. For the registration version of the software, all test mailboxes can be successfully sent. It turns out that the unregistered version contains ads and corresponding website links, 2 1cn and sina.com and other mailboxes filtered the corresponding website link, refuse to receive. 11. In order to confirm whether the recipient receives your email, when sending an email, you can increase the function of the requesting each other's receipt (OE5.5, support for Foxmail 4.2 or above). 12. Do not send too much email to the same conscript server in a shorter time interval.
