[Dovecot] Dovecot with sasl/imaps/postfix and thunderbird

[Charles Marcus]

On 2013-03-13 12:37 AM, Alex <mysqlstudent at gmail.com> wrote:
> Is it conventional to use port 143 for encrypted IMAP connections
> these days, and not just 993?

Port 143 uses STARTTLS, port 993 uses SSL/TLS... been that way for a 
long time, and yes there is a (slight) difference.
STARTTLS *begins* as an unencrypted session, but immediately negotiates 
the encrypted session. SSL is encrypted from the very beginning of the 
connection.
> I'm finding that port 25 works with TLS and postfix now too, not just
> port 587, so I'm really confused.

Both ports 25 and 587 have always worked with STARTTLS... although 
unless you have a very, very specific need, you will never FORCE 
STARTTLS on port 25, unlike port 587 where you (should) always *require* it.

-- 

Best regards,

Charles