Gmail smtp server port 25
That’s a problem, as Google Apps email accounts use smtp.gmail.com on port 465 (for SSL) or 587 (for TLS). Unencrypted sending is not possible through this SMTP server. Upon searching, I found this Google support page with the answer to my problem. The answer is to replace the smtp.gmail.com settings with: server: aspmx.l.google.com; port: 25