# Alternatives to Postal Postal is a fully-featured open-source mail delivery platform you run on your own servers, providing a REST API, SMTP, web UI for mail logs, webhooks for delivery/bounce events, and spam/virus scanning integrations (SpamAssassin, rspamd, ClamAV). It is explicitly pitched as a self-hosted alternative to SendGrid, Mailgun, and Postmark for teams that want to own their sending infrastructure and IP reputation. Postal ranks #12 of 12 in Transactional email APIs, with an Alt Score of 78. It is licensed under MIT, free from Free and available on Linux. 10 of 12 checklist rows are verified against a public source. Source: https://altcatalog.com/alternatives/postal/ Category: Transactional email APIs ## Overview - **Who it's for**: Developers and organizations who want to run their own outbound and inbound mail infrastructure for their websites or applications instead of relying on a third-party SaaS email API provider, and who are able to operate a dedicated Linux server. - **What you get**: A self-hosted, MIT-licensed mail server distributed as Docker containers, providing an SMTP relay and a JSON HTTP API for sending mail, DKIM signing, a built-in suppression list, bounce and return-path handling, click/open tracking, IP pool management, DNS health monitoring, and webhooks for message lifecycle events (sent, delayed, failed, held, bounced, clicked, opened). - **How it works**: You install Postal via Docker Compose on your own server (minimum 4GB RAM, 2 CPU cores, outbound port 25 open) and configure DNS records (SPF, DKIM, MX, return-path) for the sending domains. Outgoing mail is submitted either through SMTP credentials or the HTTP API; incoming mail can be forwarded to HTTP endpoints, other SMTP servers, or other e-mail addresses, and delivery/engagement events are pushed out to your application via configurable webhooks. Administration (servers, credentials, IP pools, tracking domains, logs) is done through Postal's own web interface. ## Profile - **License**: MIT (verified 2026-07-30) - **Pricing model**: Free (verified 2026-07-30) - **Starts at**: Free (verified 2026-07-30) - **Platforms**: Linux - **Status**: active (verified 2026-07-30) ## Ranked alternatives | # | App | Alt Score | Licence | Platforms | |---|-----|-----------|---------|-----------| | 1 | [Elastic Email](https://altcatalog.com/alternatives/elastic-email.md) | 100 | ? | Web | | 2 | [MailerSend](https://altcatalog.com/alternatives/mailersend.md) | 100 | Proprietary | Web, iOS | | 3 | [Mailgun](https://altcatalog.com/alternatives/mailgun.md) | 100 | Proprietary | Web | | 4 | [Amazon SES](https://altcatalog.com/alternatives/amazon-ses.md) | 93 | Proprietary | Web | | 5 | [Mailtrap](https://altcatalog.com/alternatives/mailtrap.md) | 93 | Proprietary | ? | | 6 | [Resend](https://altcatalog.com/alternatives/resend.md) | 93 | Proprietary | Web | | 7 | [SMTP2GO](https://altcatalog.com/alternatives/smtp2go.md) | 93 | ? | Web | | 8 | [Twilio SendGrid](https://altcatalog.com/alternatives/sendgrid.md) | 93 | Proprietary | Web | | 9 | [Zoho ZeptoMail](https://altcatalog.com/alternatives/zeptomail.md) | 93 | Proprietary | Web | | 10 | [Postmark](https://altcatalog.com/alternatives/postmark.md) | 85 | Proprietary | Web | | 11 | [useSend](https://altcatalog.com/alternatives/usesend.md) | 81 | AGPL-3.0 | Web | Alt Score = Verified coverage (90%) + Visibility (10%). See https://altcatalog.com/how-alt-score-works/ ## Feature comparison Legend: Yes / No / Partial / ? (not verified). | Transactional email APIs checklist | Postal | Elastic Email | MailerSend | Mailgun | Amazon SES | Mailtrap | |---|---|---|---|---|---|---| | Pricing model | Free | Freemium | Freemium | Freemium | Usage-based | Freemium | | Starts at | Free | $19/mo | $7/mo | $15/mo | $0.10 per 1,000 emails | $15/mo | | License | MIT | ? | Proprietary | Proprietary | Proprietary | Proprietary | | Platforms | Linux | Web | Web, iOS | Web | Web | ? | | REST API | Yes | Yes | Yes | Yes | Yes | Yes | | SMTP relay | Yes | Yes | Yes | Yes | Yes | Yes | | Deliverability tooling | Yes | Yes | Yes | Yes | Yes | Yes | | Templates | No | Yes | Yes | Yes | Yes | Yes | | Inbound email parsing | Yes | Yes | Yes | Yes | Yes | Yes | | Webhooks / events | Yes | Yes | Yes | Yes | Partial | Yes | | Suppression & bounce handling | Yes | Yes | Yes | Yes | Yes | Yes | | Dedicated IPs | Yes | Yes | Yes | Yes | Yes | Yes | | Analytics / logs | Yes | Yes | Yes | Yes | Yes | Yes | | SDKs | Yes | Yes | Yes | Yes | Yes | Yes | | EU data residency | ? | Yes | Yes | Yes | Yes | No | | Free tier volume | ? | Yes | Yes | Yes | Partial | Yes | ## Sources Sources for Postal. Each alternative is sourced on its own page. - **Starts at**: Free — (verified 2026-07-30) - Note: No paid tier exists; same reasoning as pricing_model. - Quote: “open source and ready for you to run on your own servers” - **Status**: active — (verified 2026-07-30) - Note: CHANGELOG shows regular tagged releases (3.3.5 on 2026-02-01, 3.3.6 on 2026-04-28, 3.3.7 on 2026-06-03) including security fixes; GitHub repository metadata (api.github.com/repos/postalserver/postal) - Quote: “## [3.3.7](https://github.com/postalserver/postal/compare/3.3.6...3.3.7) (2026-06-03)” - **License**: MIT — (verified 2026-07-30) - Note: Software"), to deal in the Software without restriction" — File is named MIT-LICENCE in the repo root; text is the standard MIT License wording. Copyright lines: Krystal Hosting Ltd (2017-2024), Adam Cooke (2024), Charlie Smurthwaite (2024). - Quote: “Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the ” - **Pricing model**: Free — (verified 2026-07-30) - Note: postalserver.io (the official site) permanently redirects to github.com/postalserver/install and there is no pricing page anywhere on the vendor's domains; Postal is MIT-licensed self-hosted software - Quote: “Postal is a complete and fully featured mail server for use by websites & web servers. Think Sendgrid, Mailgun or Postmark but open source and ready for you to run on your own servers.” - **Platforms**: Linux — (verified 2026-07-30) - Note: Docs are technically OS-agnostic (Docker is the only host requirement), but the same page recommends a dedicated server with 4GB RAM/2 CPU cores and open outbound port 25, which in practice means a Li - Quote: “It doesn't matter what operating system you choose as long as you are able to install Docker on it (see next section).” - **REST API**: Yes — (verified 2026-07-30) - Quote: “The HTTP API allows you to send messages to us using JSON over HTTP. You can either talk to the API using your current HTTP library or you can use one of the pre-built libraries.” - **SMTP relay**: Yes — (verified 2026-07-30) - Quote: “For sending outgoing emails through the Postal SMTP server you will need to generate a credential through the Postal web interface.” - **Deliverability tooling**: Yes — (verified 2026-07-30) - Note: Feature list also lists DKIM signing of outbound messages and per-server send-limit configuration as related deliverability controls. - Quote: “Built-in DNS checking and monitoring to ensure domains you send mail from are configured correctly for maximum deliverability.” - **Templates**: No — (verified 2026-07-30) - Note: No template engine, stored template, or merge-tag/personalization feature is documented anywhere in the docs or the feature list (docs.postalserver.io/welcome/feature-list); the API only accepts indiv - Quote: “There are two ways to send a message - you can either provide each attribute needed for the e-mail individually or you can craft your own RFC 2822 message and send this instead.” - **Inbound email parsing**: Yes — (verified 2026-07-30) - Note: The 'processed' JSON payload documented on this page includes parsed subject, from, to, plain_body, html_body, message_id, spam_status and decoded attachments. - Quote: “You can choose whether to receive the raw message (raw) or have it as a JSON dictionary (processed).” - **Webhooks / events**: Yes — (verified 2026-07-30) - Note: Documented events: MessageSent, MessageDelayed, MessageDeliveryFailed, MessageHeld, MessageBounced, MessageLinkClicked, MessageLoaded, DomainDNSError. - Quote: “Postal supports sending webhooks over HTTP when various events occur during the lifecycle of a message.” - **Suppression & bounce handling**: Yes — (verified 2026-07-30) - Note: Bounce handling detailed separately at docs.postalserver.io/other/auto-responders-and-bounces: bounces route to a dedicated return-path address and trigger a MessageBounced webhook. - Quote: “Built-in suppression list to avoid sending mail to recipients that don't exist or can't accept e-mail.” - **Dedicated IPs**: Yes — (verified 2026-07-30) - Note: Self-hosted context: since you run Postal on your own server(s), all sending IPs already belong to you (never shared with other Postal users). On top of that, Postal lets you group your own IPs into n - Quote: “Postal supports sending messages from different IP addresses. This allows you to configure certain sets of IPs for different mail servers or send from different IPs based on the sender or recipient ad” - **Analytics / logs**: Yes — (verified 2026-07-30) - Note: Same page also states: "Complete logging so delivery issues can easily be identified" and "Mail server wide search tools to find messages that need investigation." - Quote: “Graphs and stats showing volume of incoming and outgoing mail.” - **SDKs**: Yes — (verified 2026-07-30) - Note: Listed languages/frameworks: Ruby, Rails, Ruby (mail gem), PHP, Node, Java, .Net, .NET Core, Go, Elixir (via Swoosh), Drupal, Python. Page notes these aren't all developed by the Postal team. - Quote: “There are a number of client libraries available to help send e-mail using the Postal platform.” --- Ranked by verified data, never by who paid. https://altcatalog.com/trust/