Symfony Sendgrid Mailer

Symfony Sendgrid Mailer is the official bridge that connects Sendgrid to Symfony Mailer. By configuring a sendgrid+smtp or sendgrid+api DSN, your application sends mail through Sendgrid without changing how you build and dispatch Email objects.

Beyond basic delivery, the bridge handles Sendgrid-specific capabilities: inbound webhook parsing with signature validation for delivery events, suppression group headers, and email scheduling when using the API transport. It plugs directly into Symfony’s Mailer, Webhook, and RemoteEvent components.

What You Get

• SMTP and API transports selectable through a sendgrid+smtp or sendgrid+api DSN
• A transport factory that integrates with Symfony Mailer’s DSN configuration
• Webhook request parsing with optional signature validation for delivery events
• Suppression group header support for Sendgrid unsubscribe management
• Email scheduling when sending through the Sendgrid API transport

Common Use Cases

• Sending transactional email from a Symfony app through Sendgrid
• Consuming Sendgrid delivery and bounce webhooks as Symfony remote events
• Applying Sendgrid suppression groups to outgoing marketing emails
• Scheduling emails for future delivery via the Sendgrid API

Under The Hood

Architecture — The bridge is organized by Symfony component boundary: a Transport/ directory holds SendgridTransportFactory, which instantiates either SendgridSmtpTransport or SendgridApiTransport based on the DSN scheme; a Webhook/ directory holds SendgridRequestParser for inbound events with signature validation; RemoteEvent/SendgridPayloadConverter maps Sendgrid payloads onto Symfony’s MailerDeliveryEvent; and Header/SuppressionGroupHeader adds Sendgrid-specific email headers. The factory pattern lets Symfony Mailer discover the transport purely from configuration.

Tech Stack — Pure PHP 8.4+ depending only on symfony/mailer (^7.4|^8.0), with optional integration points into Symfony’s Webhook and RemoteEvent components. The package is a read-only subtree split of the main symfony/symfony monorepo, published independently on Packagist.

Code Quality — The component follows Symfony’s rigorous standards and ships a focused PHPUnit suite under Tests/ covering both transports, the transport factory, the payload converter, and multiple webhook signature cases (signed, unsigned, wrong-secret, wrong-signature). Namespacing and PSR-4 autoloading follow Symfony conventions exactly.

API Design — Developers interact almost entirely through configuration: a single DSN string selects and configures the transport, and building emails uses standard Symfony Email objects unchanged. Advanced features like suppression groups and scheduling are exposed through small, discoverable header and stamp classes, keeping the everyday path near-zero-boilerplate for existing Symfony Mailer users.