How to Send Emails in Ruby on Rails (2026)
Action Mailer is the canonical interface. Providers with a maintained Action Mailer adapter beat raw SDK use.
Sidekiq is the default for async sends. Webhook handling is straightforward with engine-style mounts.
Send patterns
- Action Mailer with a provider gem.
- Sidekiq retries on transient send failures.
- Action Mailbox for inbound parsing.
- Webhook controllers mounted under /webhooks.
Common mistakes
- Forgetting to use deliver_later in production.
- Adapter mismatch between dev (letter_opener) and prod.
- Inbound webhook signature checks skipped behind Action Mailbox.
provider picks for Ruby on Rails
- 01
Postmark
TransactionalBest-in-class Action Mailer adapter and webhook helpers.
100/mo developer plan · $15/mo for 10,000 emails - 02
SendGrid
Transactional MarketingMature gem and docs.
60-day free trial only (permanent free tier was removed May 2025) · $19.95/mo for 50,000 emails - 03
Mailgun
TransactionalAction Mailer adapter and queue-friendly.
100/day permanent free plan · $15/mo for 10,000 emails (Basic) - 04
Amazon SES
Transactionalaws-sdk-rails Action Mailer integration.
Up to $200 in AWS Free Tier credits for new accounts · $0.10 per 1,000 emails
reading this as early-stage startups
At an early stage the deciding factors are what the free tier actually covers, what the first paid invoice looks like, and how much of a founding engineer's week the setup costs. Feature depth that only matters at a million sends a month is noise until it is not.
Applied to how to send emails in ruby on rails (2026), that means weighing free tier, best published rate per 1,000, entry price, and developer experience ahead of the rest, against a waitlist, a launch announcement, onboarding email, and the first transactional sends.