[BlueOnyx:20214] POP authentication error on one network

[Lewis Gardner]

This may have been answered before but I can't find it...

I'm having problems with all Thunderbird email clients receiving email 
(POP) on one network. Users get an error:

"Sending of password for user xxxxxxxxxx did not succeed. Mail server 
xxxxxx responded: Authentication failed."


So I used PuTTY and connected via telnet to port 110. From my network I 
can connect using USER and PASS commands. From their network I get:

+OK Dovecot ready.

-ERR Unknown command.
USER xxxxxxx
+OK
PASS xxxxxxx
-ERR [AUTH] Authentication failed.

Thunderbird can send email!

Any ideas on what to do. They are using Roundcube now but the complaints 
are audible from quite a distance.


TIA