LMTP error: Mail Delivery System failed

When other user tried to sending the email to our address. Or you are trying to send the email to another user. Consequently, emails are getting bounced back to you, due to non-delivery / LMTP error. There are various possibilities behind the failure of email delivery system. In this article, we will discuss most possible cause. Let’s dig into this doubt.

Generally, in this type of situation sender get following failure email message.

This message was created automatically by mail delivery software.

A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:

user@example.com
LMTP error after end of data: 451 4.2.0 <user@example.com> Internal error occurred. Refer to server log for more information. [2016-11-29 14:44:39]:
retry timeout exceeded

Action: failed
Final-Recipient: rfc822;user@example.com
Status: 5.0.0

This means email are reaching up to recipient’s email server but not up to inbox. One of the major reason behind this is that non-existence of folders, named ‘cur’ and ‘new’. Or they might accidentally get deleted. Anyway, you must aware that all email get deleted from respective email folder when ‘cur’ and ‘new’ folder deleted. However, merely creating these two folders can help to get rid of from this obstacle.

How to solve LMTP error

  1. So, just go to cPanel > File Manager or FTP client like FileZilla, Cyberduck to create folder
  2. Navigate to home > username > mail > yourdomain.com > youremail address
    mail folder in cPanel for LMTP error
  3. Verify for existence of two folders named ‘cur’ and ‘new’
  4. If not create them
  5. Done.!

In case the folders are there, then it needs another solution

  1. Verify email address is created and wording correctly.
  2. In case forwarded, verify the email address is correctly entered.
  3. Verify MX record for domain into DNS are correctly pointed.
  4. Inbox may be full. Try to clean junk folder, unnecessary emails.
  5. Recreate the email address by deleting it after proper backup.

Hope it will solve your problem. If above solution is not worked for you, will ask your doubt in DoubtSolver Ask section with detail and screenshot (optional). We will try our best to help you there.