Note: These instructions are identical for Leopard and Snow Leopard.
Now that everything is configured and started you want to make sure that everything works. You could fire up a mail client and make it connect to the server, but here are some alternatives listed that will make it easier to test the seperate components and make it easier to debug as you see what is going on.
Postfix SMTP/TLS
To test the TLS capabilities of Postfix we will telnet to the server and try to activate the SSL session:
The server will answer with:
Connected to your.mailserver.tld.
Escape character is ^]
220 your.mailserver.tld ESMTP Postfix
Then type in:
And again your server will answer it’s capabilities:
250-PIPELINING
250-SIZE 10240000
250-ETRN
250-STARTTLS
250 8BITMIME
Now it’s time to test TLS and enter in capitals:
and the server should respond with:
Then you know this part will work.
Dovecot IMAPS
Because the configuration of Dovecot won’t allow plain password login over plain connection we have to use the IMAPS (IMAP over SSL) capabilities to test this. We’ll use the openssl client mode for testing:
The server will return a lot of output on the SSL session but should ultimatly return with:
Now we can try to login. If you haven’t created any users please use postfixadmin to create some users and mailboxes. To logon issue the following commands (with the a) and replace emailaddress and password to one existing in your setup.
Where if everything went allright the server will answer with:
Next as an extra test you could see if the INBOX folder is there:
From which the server should answer:
* OK [PERMANENTFLAGS (\Answered \Flagged \Deleted \Seen \Draft \*)] Flags permitted.
* 1 EXISTS
* 0 RECENT
* OK [UIDVALIDITY 1246736982] UIDs valid
* OK [UIDNEXT 2] Predicted next UID
* OK [HIGHESTMODSEQ 1]
b OK [READ-WRITE] Select completed.
As a last test you could ask the server to list all your users mailfolders:
If something might fail turn on as much debug information as you can. Both Postfix and Dovecot give excellent message information in the logfile. I always keep a second terminal window open where I put the command:
And I see everything that is happening in the server. If everything is working as it should turn of all the debug information as it will slow your server down.



4:34 pm
As far as I can tell I’ve done everything exactly as you’ve stated, but its not working.
When I first restarted the system port 25 was closed, then I came back to it a day later and it was open, now it’s closed again (the machine was left running the whole time).
When it was open STARTTLS failed saying Error 502 (and something about not implemented [I can't remember the exact wording]). I’ve done postfix check and status and both come back OK. Log files says “dovecot[68]: imap-login: Disconnected (no auth attempts): ….. TLS handshaking: Disconnected” when I ping port 993.