// the find
mailgun/mailgun-ruby
Mailgun's Official Ruby Library
Official Mailgun Ruby client covering the full API surface: sending, events, suppressions, templates, webhooks, domains, and more. The ActionMailer integration is the main draw for Rails shops already using Mailgun — it drops in as a delivery method with minimal config. Not a general-purpose email library; it's a thin wrapper around Mailgun's REST API.
ActionMailer integration is well done — you can attach Mailgun-specific headers (tags, tracking flags) directly on the mailer object without leaking them into your view layer. VCR cassettes for integration tests mean CI doesn't require a live Mailgun account. Test mode with `enable_test_mode!` and inspectable `Client.deliveries` is genuinely useful for unit testing mailers. EU region support is handled at client instantiation, not scattered across every call.
The gem version pinned in the README (`~>1.4.4`) is stale and will mislead anyone copy-pasting the Gemfile line. rest-client as the HTTP dependency is a liability — it's largely unmaintained and has had CVEs; most modern Ruby gems have moved to Faraday or Net::HTTP. The `Response` class just wraps the raw body with `to_h` / `to_yaml` helpers — there's no typed response objects, so you're always pattern-matching on raw string keys. Low star count (488) for an official SDK of a major email provider signals that most Mailgun Ruby users have probably moved to the Rails-native ActionMailer + SMTP path or switched providers entirely.