-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256Thanks, SMTP-AUTH was the solution to this. It was a PITA to set up, but I eventually got it working with Dovecot SASL over TLS on port 587.
Thanks for the hint! -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) iF4EAREIAAYFAlHVRJUACgkQgijxUCZnvlvImwEAsULWXgPZMN3bQbqIF/dFEPJP +hCEHaxInwezD0XQS54BAKUibbEQdM5aEYnCJT+c0evlFUxqZVXwR0EyEd/vaRkU =YtjH -----END PGP SIGNATURE-----