Sunday 25th November, 2012
Mysterious Apple Mail.app SSL issue: (or, not that mysterious, but it foxed me briefly).

If you are finding that email users using Mail.app cannot send mail, and that you are getting log lines for that user in mail.log which look like this (from a Postfix system):

postfix/smtpd[7871]: connect from host.name [x.x.x.x]
postfix/smtpd[7871]: SSL_accept error from host.name [x.x.x.x]: -1
postfix/smtpd[7871]: lost connection after STARTTLS from host.name [x.x.x.x]
postfix/smtpd[7871]: disconnect from host.name [x.x.x.x]

And this machine is also running a POP or IMAP server, then it is probably because the SMTP server and IMAP server have different certificates in use, which Apple Mail has issues with if they share a hostname. This seems to be the default situation often in the Debian packages. Aim the two at the same certificate and key file, and all shall likely be well.

posted by Rob Mitchelmore, 23:42 (anchor)