I have an email server running with Dovecot, and while trying to manage my email with Thunderbird I'm getting a weird error:
If I enable the port 143
, and 993
, Thunderbird works fine (either using 143
or 993
).
But when I disable 143
(To always force SSL), Thunderbird can not establish a connection.
I first tough that the SSL settings or certificate could be wrong, but I checked them by using the command openssl s_client -showcerts -connect imap.foo.com:993 -crlf
and everything seems to be alright.
Is it then necessary to have 143
port enabled to use the 993
for an SSL IMAP connection? Is it for being capable of establishing the first contact?
Best Answer
No, That's maybe because your configuration is not setup correctly to handle all mail communications on IMAPS(993) port.
On the dovecot main configuration file
/etc/dovecot/dovecot.conf
find and check forprotocols =
value and make sure it containsimaps
. My configuration setup there seems like this:Also you should allow port 993 on
/etc/dovecot/conf.d/10-master.conf
file. here is sample configs which working fine on my mail server:Then you should be able to block imap 143 port in firewall.