How do I troubleshoot email?

My email is not going out.

I don’t see it logged in syslog.

I can’t find an outbox or mail queue, poking around and using locate.

I don’t see any messages in the Deskbar, which is where I think I’ve seen them before. I’ve killed mail_daemon to see if the new one will give more info.

I think my configuration is okay.

Thanks for your help.

Draft mails, i.e. emails you’ve saved in Mail and didn’t send, are in ~/mail/drafts.
Sent mails are in the folder you specified in the “Outgoing” part of the E-mail preferences.

Debugging the mail_daemon is a bit harder. For some errors a window pops up, if it doesn’t you could try starting the mail_daemon from Terminal and watch if something suspicious is printed.
To avoid the launch_daemon auto-restarting the mail_daemon, you have to stop it first, then manually start it again. In Terminal:

launch_roster stop x-vnd.Be-POST
/system/servers/mail_daemon