I shifted from Hostgator to Digital Ocean, recently. On doing so, I had to setup a MTA1, on the server; for the various forms, on some personal websites, to work. I went ahead, and setup Sendmail2. I wanted to use Mandrill3 as a SMTP relay, with Sendmail2. It was a breeze setting that up to work, thanks to Di’s (a.k.a zdk), post4.
When I tried testing some of the contact forms, I realized that Sendmail2 was either hanging and/or taking upwords of 45s to send the contact form details, to me, via Mandrill3. This was totally not expected.
The FQDN5 can be a non-existent one, as long it’s pointing to localhost or 127.0.0.1.
Me, when it all started working, wonderfully.
Hope this helps someone.