Learn Docker With My Newest Course

Dive into Docker takes you from "What is Docker?" to confidently applying Docker to your own projects. It's packed with best practices and examples. Start Learning Docker →

Self Host and Preview Emails Locally with MailCatcher (Open Source)

blog/cards/self-host-and-preview-emails-locally-with-mailcatcher-open-source.jpg

MailCatcher works with any tech stack and it has a Docker image. It starts an SMTP server to view emails in a browser or any mail client.

Quick Jump: Demo Video

I’m really happy I stumbled upon https://mailcatcher.me/ when looking for a solution to preview emails in development in a secure and painless way.

I first learned about it when someone opened a PR in my example Rails Docker app with it. I kind of dismissed it because I didn’t think it was worth it, but I’ve since changed my mind.

It was super easy to get working with Flask and Rails. I’ve included it in my Build a SAAS App with Flask course as a recent update.

It hits all the marks:

  • No cloud hosted service required, it’s self hosted
  • It has a Docker image that works on both amd64 and arm64 CPU architectures and only uses about 30mb of memory
  • It has a built in web UI to view mails but you can use any mail client if you want
  • It stores emails in memory and they get purged when you stop the process
  • You can preview both html and text based emails (including attachments)
  • It updates in real-time when new emails arrive
  • It works with any tech stack (Flask, Rails, Django, Node, etc.)

You can run it and configure your web app to send SMTP based emails to localhost:1025 and preview those mails in its web UI that’s available at localhost:1080. That’s it!

The video below demos using it and how to set it up:

Demo Video

Timestamps

  • 0:10 – Keeping things local is great
  • 0:25 – The Docker image supports amd64 and arm64 devices
  • 0:47 – It works with any tech stack
  • 1:03 – I just added MailCatcher to my Build a SAAS App with Flask course
  • 1:26 – Demoing MailCatcher
  • 2:49 – A quick list of features that MailCatcher supports
  • 2:59 – Emails get sent in real-time over WebSockets
  • 3:33 – It runs in memory, emails get cleared automatically when the service stops
  • 3:53 – Integrating MailCatcher with a few web frameworks
  • 4:19 – Configuring Flask and Flask-Mail to use it
  • 6:50 – I’m really happy with MailCatcher and ultimately chose it over MailHog
  • 7:43 – MailCatcher doesn’t use a lot of disk space and it only uses ~30mb of memory

Are you using MailCatcher? Let me know below.

Never Miss a Tip, Trick or Tutorial

Like you, I'm super protective of my inbox, so don't worry about getting spammed. You can expect a few emails per month (at most), and you can 1-click unsubscribe at any time. See what else you'll get too.



Comments