Postfix timeout after DATA (0 bytes) on either smtp or submission port

If you get the following error in your Postfix log file, and email clients just appear to be hanging (e.g. stuff in Outbox):

Aug 3 08:18:59 host postfix/submission/smtpd[1353178]: timeout after DATA (0 bytes) from unknown[x.y.115.60]
Aug 3 08:18:59 host postfix/submission/smtpd[1353178]: disconnect from unknown[102.220.x.y] ehlo=2 starttls=1 auth=1 mail=1 rcpt=1 data=0/1 commands=6/7

You might be dealing with a bad network connection. Although the error is on the server, the actual problem is on the email client. Here are some options:

  • Try another network
  • Try install Windows Updates
  • Try another router, or fiddle with the MTU of your network


Share this article

Leave a Reply

Your email address will not be published. Required fields are marked *

Scroll to Top