listmonk
Mail ServersSelf-hosted newsletter and mailing list manager
Replaces Mailchimp, Sendinblue
Best API Mail Servers for self-hosting
The 22 best API mail servers you can self-host, ranked by community traction.
Postal
Mail ServersComplete mail delivery platform for outgoing email
Replaces SendGrid, Mailgun
MailHog
Mail ServersEmail testing tool with a fake SMTP server
Replaces Mailtrap
Stalwart Mail Server
Mail ServersModern all-in-one mail server in a single binary
Replaces Microsoft Exchange, Google Workspace
mailcow
Mail ServersDockerized full-stack mail server suite
Replaces Microsoft Exchange, Google Workspace
Mautic
Mail ServersOpen-source marketing automation platform
Replaces HubSpot, Marketo
Mailpit
Mail ServersEmail and SMTP testing tool with web UI
Replaces Mailtrap, MailHog
Mailu
Mail ServersSimple yet full-featured Docker mail server
Replaces Google Workspace, Microsoft 365
Mailtrain
Mail ServersSelf-hosted newsletter application
Replaces Mailchimp
Haraka
Mail ServersHigh-performance, pluggable SMTP server in Node.js
Replaces SendGrid, Mailgun
smtp4dev
Mail ServersFake SMTP server for development email testing
Replaces Mailtrap
Modoboa
Mail ServersMail hosting and management platform with a modern UI
Replaces Google Workspace, cPanel Email
Rspamd
Mail ServersFast, modern spam filtering system
Keila
Mail ServersOpen-source newsletter tool for senders
Replaces Mailchimp, Sendinblue
SendPortal
Mail ServersSelf-hosted email marketing and newsletter platform
Replaces Mailchimp
WildDuck
Mail ServersScalable IMAP and POP3 mail server with REST API
Replaces Microsoft Exchange, Gmail
Cuttlefish
Mail ServersTransactional email server with click and open tracking
Replaces Mailgun, SendGrid
parsedmarc
Mail ServersParser and dashboard for DMARC aggregate reports
Replaces Dmarcian, Valimail
Apache James
Mail ServersEnterprise mail server and SMTP/IMAP platform
Replaces Microsoft Exchange
Mailman
Mail ServersFree software for managing electronic mailing lists
Replaces Google Groups
MailWhale
Mail ServersSelf-hosted transactional email relay with API
Replaces SendGrid, Postmark
Afterlogic DAV
Mail ServersCalDAV and CardDAV server for Afterlogic WebMail
Replaces Microsoft Exchange Web Access
No apps match these filters.
Every option here is open-source and self-hostable, tagged API within the mail servers category. Compare them on the individual app pages for setup difficulty and resource requirements.