iRedmail version: 0.6.1 with MySQL backend
OS: FreeBSD 8.1

I've set up a FreeBSD iRedMail server a while ago and everything was fine. I was able to use STARTTLS (143, 465) to get and send mail from Thunderbird.
About a week ago, STARTTLS stopped working and I was getting errors about the SSL certificates and TLS related errors.
After that, I changed my ports to 993 - IMAP and 587 - SMTP (SSL/TLS settings) and it was working fine again. Now, that stopped working as well. Thunderbird just connects to the server and doesn't send any mail, it just times out.

What's going on ? The server wasn't updated and nothing changed since I've set it up.

Any help would be appreciated. Thanks.