SMTP Timeout from Remote Server As Well as Gmail Issue

I installed mailinabox a month ago and liked it very much. Then I needed to use the SMTP feature but it always timed out on my websites. The setup seems perfectly normal according to the docs. i.e. I tried to use email[1] as SMTP email on so there shdouldn’t be any issue. Please help, how to figure this out? My email server is hosted on a droplet with Digital Ocean. Moreover, I tried the TLS over port 587. In addition, mostly emails from gmail take long to land in my inbox and sometimes I even don’t receive them at all. Any help will be appreciated greatly.

  1. Make sure your IP Address is not blacklisted: ( has a tool for this)
  2. MIAB uses a feature called Greylisting, so any email originating from a server your MIAB has not seen will be held for 10 minutes to help prevent spam
  3. Make sure you are sending to the right email address as some SMTP servers will not report a bounce back after accepting an email but rejecting the recipients.

Thank you for your input on this. I’ve set up a new server and will consider your tips there.