Locating mutt logs

[Peter Flynn]

I installed mutt 1.13.2 from the system repos on Mint 20.3 in order to 
be able to force some wayward messages into the threads where they belong.

That works fine on this address, so I have been trying to add more of my 
accounts on various other servers, but some of them clearly try to 
connect, but immediately claim "Login failed" with no other information, 
which is not useful.

The usernames and passwords are correct (the accounts are all working OK 
in Thunderbird), but I cannot find any kind of connection log that would 
let me find out what is going on. The file /var/log/maillog does not 
exist, although /var/log/mail.log does, but is empty. syslog and 
auth.log entries have no indication of anything to do with mutt.

Is it possible to turn logging on without having to compile my own mutt 
from source? Or should I look for logs elsewhere?

Peter