Postal review: self-hosted, open-source mail delivery platform for outbound and inbound email. Features, setup notes and top alternatives.
Postal is an open-source mail delivery platform that organizations install on their own servers to send and receive transactional and marketing email, giving them a self-hosted alternative to metered, hosted email-sending APIs.
Originally built internally by UK hosting company aTech Media (now Krystal) under the name AppMail, Postal was open-sourced in 2017 under the MIT license and has since been adopted by developers and agencies who want full control over their mail infrastructure and delivery reputation.
Postal provides a web dashboard for monitoring message delivery, bounces, complaints and queue status, along with an HTTP API and SMTP interface for sending mail programmatically from applications, plus webhook support for reacting to delivery events.
It supports multi-tenant organizations and mail servers within a single Postal installation, DKIM signing, and both inbound and outbound mail handling, letting teams run a complete transactional and marketing email pipeline without relying on a third-party SaaS provider.
Postal itself is free and open source under the MIT license, with no licensing fee for the software; the only costs are the servers used to host it, which teams provision and manage themselves (typically a mail-focused VPS or dedicated server with appropriate IP reputation).
Teams that do not want to self-host can use third-party managed hosting providers, such as Elestio, that offer Postal as a managed service for a monthly fee, but this is a separate offering from the open-source Postal project itself.
Yes, Postal is free, open-source software under the MIT license; the only cost is the server infrastructure you host it on, unless you use a paid managed-hosting provider.
Postal and Postmark share a similar name but are unrelated products: Postal is free, open-source and self-hosted, while Postmark is a commercial, hosted email-sending API with no self-hosted option.
Postfix is a low-level mail transfer agent that only routes SMTP mail with no UI or API; Postal is a full mail delivery platform with a web dashboard, REST API and message tracking, built on top of the mail-transfer layer.
Postal was originally built by UK hosting company aTech Media (now Krystal) for its own mail needs and released as open source in 2017.
Yes, Postal supports both sending outbound transactional/marketing email and receiving inbound mail.
Postal is released under the MIT license.
Teams that prefer not to self-host can use hosted providers like Postmark, SendGrid, Mailgun or Amazon SES, or use a third-party managed-hosting provider that offers Postal as a service.