[ Thanks to Andrew
Weber for this link. ]
“Thunderbird Client Configuration
Client configuration can be just as big of problem as the set up
for the server. One of the problems is that not all clients, both
Linux and Windows, are capable of handling TLS or SMTP AUTH. That
is getting better but it is still a problem. One great alternative
client is Thunderbird, Icedove if you are on Debian. Here is a step
by step approach to setting up the Thunderbird client for TLS and
SMTP AUTH.“In the example, IMAP is the server of choice. This allows you
to retrieve mail and also leave the mail on the server so you could
share accounts. An important setting is the “Incoming
Server”. Make sure you enter a FQDN (Fully Qualified Domain
Name) which means it must have a hostname and domain name.”