Connection Times Out

nekton181

I am new to Mailcow but can’t seem to find the answer to my question in the docs or faq.

I set up Mailcow as my second email server behind my firewall.

I am able to send and receive email from Mailcow to/from my Gmail account. I am able to send email to my original email server. When I try to send email from my original email server to Mailcow, the original email server logs show it times out trying to send the message.

Someone suggested that there might be something in Mailcow set up that is blocking email from my original email server.

I don’t know where to start to check such things in Mailcow. If I wanted to whitelist email coming from my original email server to Mailcow, how might I go about it?

If there is a link to documentation that would explain this or some tests I could run to verify my original email server is being blocked by Mailcow, I would appreciate it.

If there are configuration files or log files that I should post, please let me know.

Thanks so much for any help that can be provided.

nekton181

Sorry for replying to my own post but I ran a docker-compose logs command for the Mailcow email server and found some entries like this:

postfix-mailcow_1 | Feb 10 03:18:51 a8eeb4734942 postfix/smtp[5274]: 8
7BB2320A4B: to=foo@oldemailserver.com, relay=none, delay=38706, delays=38696/0.
04/10/0, dsn=4.4.3, status=deferred (Host or domain name not found. Name service
error for name=oldemailserver.com type=MX: Host not found, try again)

I don’t understand why this is showing up as the DNS clearly has a MX record in it for oldemailserver.com which is happily being used by many other email servers.