Kmail successfully sends an email and will receive a Bounce Message. How can this problem be solved?

We useKmailWhen an email is sent by an email tool, you may receive a message indicating that the email is successfully sent, but you will receive a Bounce Message later. For more information, see the following.

Because the transmission of mail is completed by the servers of both parties, if it fails, a bounce message will be generated. If the recipient does not receive the email when you use Kmail to send it to other mailboxes, and a Bounce Message appears in your mailbox, You can query the content of the Bounce Message for analysis, the reason will be detailed in the return letter:

1. No such Recipient: The Bounce Message is generally invalid address (#5.5.0), User unknown, or user is not found. A similar prompt may be related to the recipient's address that does not exist or is incorrect. It is generally because the email address @ is incorrect. Please check with the recipient whether the email address is correct.

2. without this host: The Bounce Message is generally Sorry, I couldn't find any host named kail.com.cn. (#5.1.2) the cause is generally that the recipient's email address @ is followed by an error. For example, if @ sina.com is written as sian.com, this error may also occur when DNS resolution fails.

3. When the recipient's mailbox is full, the message returned is generally: receiptor's mailbox is full (#5.5.4) or user Quota is over. The reason is that the recipient's mailbox exceeds the permitted capacity. You can only contact the recipient by other means, ask the recipient to clear the mailbox and then receive it.

4. the Recipient's server refuses to receive the Kmail email Bounce Message. Generally, the message is: Recipient address rejected: Relay access denied or 552 Error: content rejected because the Recipient's email server has blocked Kmail. Please forward the bounce message to us in the form of an attachment. I will perform a test to determine the cause of the problem and then contact the other party, describe our server information and discuss the solution to the problem. At the same time, you also hope that you can use other mailboxes to reflect the problem to the other party and contact the other party to inform the network administrator of the situation to ensure that the problem can be solved as soon as possible.

5. the size of the email you send to the recipient exceeds the permitted range of the recipient. The Message is generally 552 Message size exceeds fixed limit because your email is too large to exceed the recipient's email size limit, compress the attachments in the email or send them in batches.

6. when the recipient's server is busy generating a bounce message, the system prompts that an SMTP connection-Sorry, I wasn' t able to establish an SMTP connection cannot be established. (#4.4.1) or 550 System is busy. this prompt should be related to the fact that one of the other's servers is busy or the connection to the Kmail mail server is not smooth. This may be a temporary issue. Please try again by sending an email for testing.

By reading the article, I believe that those who encounter the same problem will learn the solution through the above six points. I hope you can use it!

• Solution to Kmail failure to receive emails from the recipient
• Kmail Setting Process
• 3.2.3 tips 052 Other precautions for Kmail Configuration
• 3.2.2 tip 051 how to configure email sending and receiving in Kmail
• 3.2.1 tip 050 how to add a signature in Kmail
• Microsoft CheckMail password leakage Vulnerability
• KDE KMail HTML EMail remote Email spoofing content Vulnerability