# basecamp/mail_view

Visual email testing

Repository: https://github.com/basecamp/mail_view
Canonical: https://ross.abutalabs.com/products/mail_view
Language: Ruby
License: MIT
License Family: permissive
Archived: true
Last push: 2018-02-08T08:07:12+00:00

## Health v2 (maintenance only)
Score: 10/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 0, release rhythm 35, longevity 100
- inputs: {"age_days": 5978, "days_push": 3128, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases, archived
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1321, forks 128 (observed 2026-08-28T04:04:21.948034+00:00)

## What it is
MailView is a Ruby gem that lets Rails developers preview plain text and HTML email templates in a browser without actually sending mail. It was merged into Rails 4.1+ as ActionMailer previews, so the standalone gem is largely superseded.

## Use cases
- preview email templates in the browser during development
- test mailer views without sending real emails
- render emails with fixture or factory data
- visually inspect plain text and HTML email output
- set up mailer preview scenarios like unit tests

## When to choose
- you maintain a legacy Rails 2.x or 3.x app that predates built-in mailer previews
- you want a lightweight standalone email preview tool for non-Rails-4.1 Ruby projects

## When to avoid
- you are on Rails 4.1 or later, which includes ActionMailer previews natively
- you need actively maintained software with recent releases
- you need email testing features beyond simple visual preview, such as delivery interception

## Facets
- artifact type: library
- maturity: maintenance
- function: testing, email, web-framework, templating
- domain: web-development, testing, developer-tools, email
- platform: ruby, self-hosted
- tags: email-previews, action-mailer, rails, mail-templates, development-tools, web-server

## Member repositories
- basecamp/mail_view (main) score 10

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:04:21.948034+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T04:47:16.923280+00:00, confidence not recorded.
  - readme: https://github.com/basecamp/mail_view (fetched 2026-08-28T04:04:21.948034+00:00, sha 8f8f5608af04)
- Data as of 2026-08-30T08:39:29.467469+00:00.