[haroldp]

On my laptop, where I do all of my development work, I just configured Postfix to send everything to plain files:

http://harold.internal.org/configuring-a-dev-box-mail-server...

I like this a lot better than sending stuff out across the network.

[hobarrera]

https://github.com/mailhog/MailHog looks like a really nice alternative, where you can also test HTML mail, etc.

Personally, my local SMTP actually sends email, because I DO want legitimate email (mutt, cron) though, so I'd be scared to mix up two local smtp instances.

[peller]

MailHog is pretty great. In response to your concern, by default it runs on a non-standard port, so you need to configure your apps to point at it (port 1025 by default). Even then, you can configure it to act as a MITM, where the webmail interface lets you "release" messages you actually want to send out: https://github.com/mailhog/MailHog/blob/master/docs/CONFIG.m...

[xanderstrike]

Mailcatcher is an even simpler solution (assuming you can install rubygems): https://mailcatcher.me/

[Arcsech]

Mailcatcher is available as a Docker container, so you don't even necessarily have to set up Rubygems yourself: https://hub.docker.com/r/schickling/mailcatcher/

[tijn]

I recently ported a small combined SMTP/POP3-server (from Ruby to Crystal) so I can read the mail from my projects in Thunderbird or the OS X Mail app. Yes, this is another shameless plug, but I hope it's useful: https://github.com/tijn/devmail