What is swiftmailer?

swiftmailer/swiftmailer — explained in plain English

Analysis updated 2026-06-24

★ 9,459PHPAudience · developerComplexity · 2/5LicenseSetup · easy

Mindmap

mindmap
  root((repo))
    Status
      End of life 2021
      No active support
    Replacement
      Symfony Mailer
      Same team built it
    Original features
      Compose messages
      Connect mail servers
      Deliver email
    License
      MIT permissive

mindmap root((repo)) Status End of life 2021 No active support Replacement Symfony Mailer Same team built it Original features Compose messages Connect mail servers Deliver email License MIT permissive

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What do people build with it?

USE CASE 1

Migrate a legacy PHP project that uses Swift Mailer to Symfony Mailer using the migration guide

USE CASE 2

Reference the original API design to understand how to port email-sending code to a modern library

What is it built with?

PHP

How does it compare?

	swiftmailer/swiftmailer	phpdocumentor/reflectiondocblock	dingo/api
Stars	9,459	9,387	9,352
Language	PHP	PHP	PHP
Setup difficulty	easy	easy	moderate
Complexity	2/5	2/5	3/5
Audience	developer	developer	developer

Figures from each repo's GitHub metadata at analysis time.

How do you get it running?

Difficulty · easy Time to first run · 30min

Library is no longer maintained since November 2021, use Symfony Mailer for all new projects and migrations.

Use freely for any purpose, including commercial use, as long as you keep the copyright notice.

So what is it?

Swift Mailer is a PHP library for sending email from web applications. It handles the mechanics of composing messages, connecting to mail servers, and delivering email, giving developers a structured way to send mail rather than using PHP's basic built-in mail function. The library is no longer maintained. The README states plainly that support ended in November 2021 and that users should move to Symfony Mailer, which the same team developed as a replacement. Symfony Mailer covers the same use cases and adds support for modern PHP features and third-party email service providers. Beyond noting its end-of-life status and pointing to the replacement, the README does not go into detail about features or usage. The full documentation was hosted externally. The library is released under the MIT license.

Copy-paste prompts

Prompt 1

I have a PHP project using Swift Mailer that I need to migrate to Symfony Mailer. What are the key API differences in how messages are created and transports are configured?

Prompt 2

Convert this Swift Mailer code to Symfony Mailer: a Swift_Message object sent via $mailer->send(), show me the equivalent Symfony Mailer code.

Prompt 3

What are the main improvements in Symfony Mailer over Swift Mailer, and which transport should I choose for sending through Gmail or SendGrid?

Frequently asked questions