Postal
Postal is an open-source mail delivery platform for applications. It provides an HTTP sending API, SMTP submission, message logs, and incoming-message routing; it is not a general-purpose IMAP mailbox server.
Use it when you want to operate your own delivery infrastructure. You remain responsible for the host, DNS, authentication records, reputation, monitoring, and backups. Start with installation, then choose sending, inbound routing, or migration.
These guides follow Postal's official documentation. There is no released Postal-specific MailKite SDK in this guide; the integration steps describe supported configuration and APIs.
Explore the guides
How to install Postal v3 on a VPS
Install Postal v3 on a dedicated server, configure MariaDB and DNS, start its containers, and verify the web interface before sending.
Send email with the Postal API from Node.js
Call Postal's HTTP API from Node.js, handle its JSON result safely, and compare the same application send with MailKite's SDK.
Receive inbound email with Postal HTTP routes
Route inbound Postal messages to an HTTPS endpoint, acknowledge requests safely, and handle retries, parsed payloads, and attachments.
Migrate transactional email from SendGrid to Postal
Plan a SendGrid-to-Postal migration by mapping API calls, domains, templates, events, DNS, and rollback before switching application traffic.