Mark Labeste writes:

...

From mailman web it was able to deliver the email to outlook and gmail but when replying or confirming subcription it can't reach the mailman.

This error is bounce back from outlook. Server at destination.email.com (192.10.10.10) returned '400 4.4.7 Message delayed' 1/4/2024 12:16:13 PM - Server at destination.email.com (192.10.10.10) returned '451 4.4.397 Error communicating with target host. -> 421 4.2.1 Unable to connect -> SocketTimedout: Socket error code 10060

This is not a Mailman problem, unless Mailman is not running. If that's the case, start it. If it won't start, or starts and crashes (including individual runners crashing, this should be reported in Mailman's 'mailman.log' file)), tell us about that.

Assuming "destination.email.com" is your MX host and Mailman is on a different host, I can think of the following possibilities:

• There's a firewall between "destination" and Mailman, and it doesn't pass traffic to Mailman's LMTP server (usually on port 8024).
• "destination" is configured to send Mailman traffic to the wrong host or wrong port, or both.

If something else is going on, we need to know about that.

Steve