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MailDev

MailDev is a lightweight simple mail transfer protocol (SMTP) server and web interface for viewing and testing emails during development.

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MailDev is a lightweight simple mail transfer protocol (SMTP) server and web interface for viewing and testing emails during development. It captures outbound development messages and displays them in a local web interface, making it useful for developers who need a local SMTP endpoint without sending real email.

Platform availability

Available on 2 of 9 platforms

  • Unraid
  • TrueNAS (not listed)
  • Umbrel (not listed)
  • ZimaOS (not listed)
  • Proxmox (not listed)
  • Helm
  • Mac (not listed)
  • Windows (not listed)
  • Linux (not listed)

Health score?A 0-100 score computed nightly from four factors: maintained (40%: recent commits and steady activity), popular (25%: GitHub stars, log scale), easy to install (20%: platforms, install notes, setup guides, Docker image) and light to run (15%: minimum RAM, ARM support). When the source code has been checked, a fifth factor, security check (20%: automated scan for committed secrets, unsafe desktop-app settings, known-vulnerable dependencies and project hygiene; any serious finding caps it at 20), is added. Factors without data are left out and the rest are rescaled.

80/100 Excellent

Maintained
100last commit 19 days ago
Popular
766,127 GitHub stars
Easy to install
452 install platforms, install notes, Docker image
Light to run
No data

Based on 3 of 4 factors.

Availability: platform listings confirmed today, links checked 15 days ago

GitHub stars
6,127
Open issues
43
Last commit
2026-09-24
Latest release
[email protected]
License
MIT
Activity
unknown

Checked 7 days ago - source: GitHub (maildev/maildev)

Resources & Compatibility

ARM (e.g. Raspberry Pi) is supported.

Checked 14 days ago - source: Docker Hub image tags and published docs

First-install notes

  • Install MailDev from npm Use npm (Node's package manager) to install MailDev, for example with npm install -g maildev, so the maildev command exists on your machine. Without this step, you cannot start the app from the terminal. source
  • Open ports 1025 and 1080 MailDev uses port 1025 for receiving test emails (SMTP) and port 1080 for the web UI/API. If either port is blocked in your router or firewall, emails will not arrive or the web page will not load. source
  • Add HTTPS if you need secure access If you want to use MailDev over HTTPS, start it with --https and point --https-key and --https-cert to your SSL key and certificate files. Without this, MailDev stays on plain HTTP, which may be insecure for remote use. source

Fetched 14 days ago - each note links to its source

Alternatives (7)

  • FakeSMTP - FakeSMTP is a Free Fake SMTP Server with GUI for testing emails in applications easily.
  • MailCatcher - MailCatcher runs a super simple SMTP server which catches any message sent to it to display in a web interface.
  • MailDrop - MailDrop is a free throwaway e-mail address.
  • Mailpit - Mailpit is a multi-platform email testing tool & API for developers.
  • Mailtrap - Mailtrap is an Email Delivery Platform for businesses and individuals to Test, Send, and Control their email infrastructure performance.
  • Papercut - Papercut is a simplified SMTP server designed to only receive messages (not to send them on) with a GUI on top of it allowing you to see th…
  • mailhog - MailHog is an email testing tool for developers that captures outgoing SMTP messages locally, shows them in a web UI or JSON API, and can o…

Checked 11 days ago - source: AlternativeTo

Common questions

Which ports must be available for MailDev to work?

Port 1025 receives SMTP mail and port 1080 serves the web inbox and API. If either port is blocked, mail will not arrive or the web page will not load.

How do I connect an app running in Docker to MailDev?

If MailDev runs in Docker, do not use localhost from the app because localhost points to the container. Use the MailDev service name or host.docker.internal as the SMTP host.

Can MailDev forward selected development emails to a real SMTP service?

MailDev can selectively relay individual emails to a real outgoing SMTP server. Configure the outgoing SMTP options, then use the Relay action on the email you want to send.

How do I serve the MailDev web interface over HTTPS?

Start MailDev with --https and point --https-key and --https-cert to your SSL key and certificate files. Otherwise, the web interface remains on plain HTTP.

Answers sourced from github.com, github.com, github.com, maildev.github.io

Community

Collected 8 days ago - public community threads