Postal

Development mode holds outgoing messages inside Postal so they can be inspected without delivery to recipients. That provides a useful first step when connecting an application: check the generated receipt or password-reset message in the interface before moving the sending configuration into normal use.

An organization can contain several mail servers, each with its own credentials, sending limits and retention settings. Tags group message types for investigation. The interface exposes incoming and outgoing queues, historical messages and delivery logs; webhook request history is retained for seven days to help trace event notifications.

Postal also routes incoming messages to HTTP endpoints, other SMTP servers or email addresses. Operating it requires the team's own server infrastructure. The core repository is MIT-licensed, while integrations such as external spam and virus checking have their own setup requirements.

After the installation prerequisites and configuration are ready, the setup guide uses postal initialize to prepare the database and postal make-user to create the first administrator. Sign in to the web interface, create an organisation and mail server, then add the sending domain and publish its DNS records. Create an SMTP or API credential before sending a test message. Postal handles mail transport; contact lists and unsubscribe management belong in the application connected to it.