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MailHog

A fake mail server for testing: catches outgoing email and shows it in a web inbox.

GitHub Download v1.0.1
Stars
16.2k
Forks
1.2k
Licence
MIT
Language
Go
Last update
2.7 years ago
Type
Dev tool

No commits in over a year — check for forks or alternatives before adopting.

What it is

MailHog is a small testing tool that acts as a stand-in mail server during development. Your application sends email to it instead of a real provider, and MailHog stores those messages so you can view them in a web interface or fetch them through an API. It can also forward messages to a real SMTP server when you choose to.

  • Point a local app's SMTP settings at port 1025 and view sent emails at port 8025
  • Read captured messages in the web UI as plain text, HTML, or raw source
  • Use the JSON API to list, retrieve, or delete messages in automated tests
  • Release a captured message to a real SMTP server when you need to test real delivery

Great for

  • Developers testing sign-up, password reset, or notification emails locally
  • QA or teams who want to inspect outgoing email without sending it to real inboxes
  • Projects that need an automated way to check sent messages through the HTTP API
  • Anyone who wants a simple alternative to heavier mail testing setups

Not ideal for

  • Production email delivery, since MailHog is a testing tool and does not deliver mail to real recipients by default
  • People who need persistent, large-scale mail storage; the README lists in-memory storage by default, with MongoDB or file storage as options
  • Teams needing active maintenance guarantees, since the last push shown is February 2024 and the README references older Go versions
Step-by-step guide: how to use MailHogInstall, first run, examples, tips and FAQs
MailHog vs Mailpit

How to get it

  1. 1

    Install with a package manager

    You'll need: Homebrew (macOS) or Go 1.17+ for the go install route

    macOS install via Homebrew

    brew update && brew install mailhog

    Go install (Go 1.17 or newer)

    go install github.com/mailhog/MailHog@latest
  2. 2

    Run it

    • Install MailHog using one of the README methods
    • Start it by running `mailhog` in a terminal (or the path to the MailHog binary)
    • Configure your application to send SMTP to the MailHog host on port 1025
    • Open the web interface on port 8025 to view captured messages
  3. 3

    Get the most out of it

    • Use the HTTP API (APIv1 and APIv2 docs are linked in the README) to check messages in automated tests
    • Enable HTTP basic authentication for the UI and API using the linked Auth guide
    • Use the Chaos Monkey feature (Jim) to test how your app handles mail failures
    • Use mhsendmail or `MailHog sendmail` to act as a sendmail replacement, for example with PHP's sendmail_path

Downloads

Source code (.zip)master branch · straight from GitHubRelease v1.0.16 files incl. MailHog_darwin_amd64

Strengths

  • Simple setup with defaults: SMTP on port 1025 and web UI on port 8025
  • Runs as a single portable binary with no installation required, per the README
  • Supports both a web UI and an HTTP API for checking messages

Trade-offs

  • Default in-memory storage means captured messages are lost when it stops
  • The README's build and install notes reference older Go versions and the last push shown is from 2024
  • Documentation is brief in the README, so advanced options require reading linked docs

How it compares

ProjectStarsTypeLevelUpdatedBest for
MailHog (this)16.2kDev toolbeginner2.7 years agoDevelopers testing sign-up, password reset, or notification emails locally
mailpit10.8kDev toolbeginner4 days agoDevelopers testing signup, password reset, or notification emails locally

Stats synced from GitHub. The assessment above was drafted with AI from the project's README on 2026-10-29 and may miss recent changes — check the README before relying on a command. MIT licence: free to use, modify and distribute, including commercially, as long as you keep the copyright notice.