Whoever will need this in the future:

 I suddenly (everything was working fine for a few years) had the same problem running Mercury as service (by the help of NSSM utility), while running it as application with GUI did not reproduce the problem.

Analyzing the activity of the server with the help of Process Monitor utility, I found that it was not able to read the certificate file.

As soon as I assigned read permissions for the SYSTEM account (which is used while running as service) the problem was solved.

ps: thanks for the irreplaceable mail software :)  

Intermittently, Mercury 4.72's IMAP window stats showing [Not-logged-in] or "SSL direct connect failure from x.x.x.x". The only solution I have found is to restart Mercury. This problem may occur a couple of days after a Mercury restart, or today it happened after several hours. It always works after Mercury is restarted.

Here are the session logs for each type of connection:

08:43:37.796: Connection from 97.239.79.164, Sat Jun 19 08:43:37 2010<lf>
08:43:37.796: << * OK po.pi-usa.us IMAP4rev1 Mercury/32 v4.72 server ready.<cr><lf>
08:43:37.937: >> 1496 STARTTLS<cr><lf>
08:43:37.937: << 1496 OK Begin SSL/TLS negotiation now.<cr><lf>
08:43:37.937: 20: Error -3 creating CryptLib session.
08:43:37.937: --- Connection closed normally at Sat Jun 19 08:43:37 2010. ---
08:43:37.937:

08:48:47.515: Connection from 67.223.76.217, Sat Jun 19 08:48:47 2010<lf>
08:48:47.515: 20: Error -3 creating CryptLib session.
08:48:47.531: --- Connection closed normally at Sat Jun 19 08:48:47 2010. ---
08:48:47.531:

If I connect to the IMAP via the Apache web server on the same machine, I can connect even when the other connections are failing.

Any ideas what is wrong?

Thanks.

 -jeff

I would check the settings on Mercury and ensure they are correct for the SSL/TLS connection, maybe it's something like disabling weak authentication that's preventing the SSL connection from being established. Could it also be an issue with the client not accepting the self signed certificate if you are using one?

Just some ideas...

After proudly reporting two days ago that I had IMAP working over SSL, I ran into the same problem this morning. Neither the configuration of Mercury, neither the configuration of my two test clients had changed. Restarting Mercury didn't work.

What worked for me is very trivial: in the configuration of the IMAP server, SSL tab, I browsed for the certificate. It now appears as a full name including its directory: instead of my_certificate its now c:\mercury\my_certificate.

Could it be that for some reason Cryptlib couldn't find the certificate?

Bart