hMailServer for Outbound Only SMTP Server

If you ever needed to write program that sends email, most likely you’ll need a SMTP server. Here’s how you can configure one on a Windows box using hMailServer.

New Domain

After downloading and installing, you need to add a new domain to hMailServer. In my case I will not be using hMailServer to accept incoming email, hence I did not put the company’s email domain. Doing so will cause email to your colleague to be routed locally and likely fails.

So go ahead add a new domain, and just give it the local machine name (eg: devbox01.local). You have to pick a name that resembles an actual domain (with a dot and suffix), otherwise hMailServer will rejects it.

New Account

Once you’ve setup the domain, create a new account noreply@devbox01.local

hmail

Set a password, and that’s it you’re done. You can now use the SMTP server for outbound email

  • Username: noreply@devbox01.local
  • Password: whatever password you put in
  • SMTP host: devbox01
  • SMTP port: 25

Important

Now what’s left to do is configuring firewall. If you program runs on the same box you might not need to do anything. However it’s good to check that no outside traffic from internet can connect to port 25 so no-one can abuse your SMTP server.

And as a last word of warning, do not assume all mails will be delivered. This SMTP setup is very basic. Depending on the content you send, SPF, reverse DNS entry, spam filtering of receipient, and gazillion other things, your email might not go through