Email delivery failed

Email delivery failed: Problems and solutions

Sometimes we encounter problems, such as "Email delivery failed" which can be quite frustrating. We may wonder what happened, why emails aren't reaching the recipient, and how to fix this problem. This web page focuses on resolving your questions regarding "Email cannot be sent" from the cause of the problem to interpreting the meaning of notification messages and providing useful solutions. Whether you are the sender or recipient of an email that failed to send, this article will help you understand the cause of the problem and provide quick fixes.

How to read bounce messages:

The message is in a standard and slightly obscure format, intended to be read by both humans and robots, the key line to examine is this one

For [email protected], REASON

That will tell you the address mail server was trying to deliver the message to, and the reason it failed.

The wording of the 'reason' should indicate if the problem was on the mail server reporting the problem or on the mail server it was trying to deliver your message to. Always consider this point carefully so that you try and fix the problem on the right mail server (or by emailing the correct mail server administrator)

Invalid Domain (xxx.yyy.com)

This means the name server was unable to find an 'mx' record for the domain in question. There are many possible causes for this error. Including:

  1. The domain name may be miss spelled
  2. The domain name may have a trailing space or other unintentional characters
  3. The domain may have MX records which point to names that don't have 'A' records.
  4. The domain may not exist

open (n.n.n.n) 23s failed

This error usually means the remote system is not running, or you have a network fault somewhere between your mail server and the destination server. Check if you can connect to the remote server manually

Here is the full text of the error:

For , open (NNN.NNN.NNN.NNN) 23s failed A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond. 23 sec

Mailbox Not Found, User unknown, etc...

โดยทั่วไปหมายความว่าคุณสะกดที่อยู่ปลายทางผิดหรือผู้ใช้เปลี่ยนที่อยู่

Mailbox full, or Quote Exceeded:

This generally means you have miss spelled the destination address or the user has changed their address.

Host unknown, Domain Lookup Failed:

This means the destination user has run out of disk quota and cannot receive new messages until they have deleted some. It may mean that the recipient has stopped reading the account completely.

Unable to Relay

This could be caused by a DNS failure or the destination domain may not exist. More likely you have miss spelled the domain name.

If you get this error during a local send you may need to enable SMTP authentication in your email client.

Temporary Errors: "no adequate servers", "Connection Timed Out", "Resources temporarily unavailable.", "Out of memory"

These are usually temporary errors, it is worth retrying.

This usually means your isp's mail server has been black listed, the problem will probably be fixed in 24 hours.