[Mailman-Users] Only one list not working

[Javier]

¡Hello to everyone!

Only one of my lists does not work, the web interface of this list does.

When I send an email the list after a while I receive a message with the 
rejected connection.

In the Postfix log I don't see any errors and the telnet connection 
works. I don't see any errors in Mailman's logs either, but they are 
strangely empty.

Can you think of what the mistake might be?

Thank you in advance. Greetings.