How to setup an SMTP server on Mac OS X?

The following did the job. See source here.

1. Edit file: sudo emacs /System/Library/LaunchDaemons/org.postfix.master.plist.
2. Add <key>RunAtLoad</key> <true/> <key>KeepAlive</key> <true/> before the closing </dict> tag.
3. Run sudo postfix start.

Check that SMPT is running: telnet localhost 25

Option 1:

CommandLineFu had this one liner to run an SMTP server on port 25:

sudo python -m smtpd -n -c DebuggingServer localhost:25

This will run a fake smtp server on your local machine. It won't send anything, but will dump it to the console.

Option 2:

Incase, you are not comfortable with command line then FakeSMTP is a Free Fake SMTP Server with GUI for testing emails in applications easily. It is written in Java. It is very nice and easy to use.

[http://nilhcem.com/FakeSMTP/][1]