Don't use the 14.0v1 installer for El Capitan. FMI has noted issues with it in the past and I know a new base installer was released at least with 14.0v3. If you contact your licensing rep they can issue a new download link based on your license key for the current installer. It's worth the wait for that updated email to save on the headaches.
For GMail you should be setting up an SMTP relay account, which GMail uses to authenticate external apps sending permissions in a more stable, secure method.
That comes with a different SMTP server address.
Also, I don't think you can use port 25 for SMTP, 465 and 587 are the alternate ports for SSL and TLS respectively.
Thanks for the message.
I've received the new downloads from FileMaker which is helpful.
Interesting that two other locations use smtp.gmail.com on FMS 14, both using port 25.
I'll look into the google apps. Thanks for that heads-up.
Moore Brothers Wine Company
New Jersey, Delaware, New York City