Mailspring
Mail ServersCross-platform desktop email client
Replaces Outlook, Apple Mail
Best Free Mail Servers for self-hosting
The 71 best Free mail servers you can self-host, ranked by community traction.
MailHog
Mail ServersEmail testing tool with a fake SMTP server
Replaces Mailtrap
Mail-in-a-Box
Mail ServersTurn a fresh server into a working mail server
Replaces Google Workspace, Microsoft 365
Mailpit
Mail ServersEmail and SMTP testing tool with web UI
Replaces Mailtrap, MailHog
Himalaya
Mail ServersModern command-line email client written in Rust
Replaces Mutt, Outlook
SimpleLogin
Mail ServersOpen source email alias solution to protect your email address
MailCatcher
Mail ServersCatch-all SMTP server for inspecting test email
Replaces Mailtrap
AnonAddy
Mail ServersEmail forwarding service for creating aliases
imapsync
Mail ServersSynchronization and migration tool between IMAP accounts
Replaces IMAP migration services
smtp4dev
Mail ServersFake SMTP server for development email testing
Replaces Mailtrap
NeoMutt
Mail ServersFeature-rich terminal email client
Replaces Microsoft Outlook
aerc
Mail ServersEfficient terminal-based email client
Replaces Gmail, Outlook
Dittofeed
Mail ServersOmni-channel customer engagement and messaging automation platform
SendPortal
Mail ServersSelf-hosted email marketing and newsletter platform
Replaces Mailchimp
emailwiz
Mail ServersScript to deploy a full Postfix/Dovecot mail server
Replaces Google Workspace
Mailvelope
Mail ServersBrowser extension for OpenPGP encryption in webmail
Replaces ProtonMail
iRedMail
Mail ServersFree, full-featured mail server solution
Replaces Microsoft Exchange, Google Workspace
Forward Email
Mail ServersPrivacy-focused encrypted email for everyone
DebOps
Mail ServersYour Debian-based data center in a box
swaks
Mail ServersSwiss Army knife for SMTP testing
Replaces Mailtrap
parsedmarc
Mail ServersParser and dashboard for DMARC aggregate reports
Replaces Dmarcian, Valimail
Dovecot
Mail ServersSecure, high-performance IMAP and POP3 server
Replaces Microsoft Exchange
Apache James
Mail ServersEnterprise mail server and SMTP/IMAP platform
Replaces Microsoft Exchange
Nextcloud Mail
Mail ServersIMAP webmail client integrated into Nextcloud
Replaces Gmail
Betterbird
Mail ServersCommunity-enhanced fork of the Thunderbird email client
Replaces Microsoft Outlook
Sup
Mail ServersConsole-based threaded email client
Replaces Mutt
OpenTrashmail
Mail ServersComplete trashmail solution that exposes an SMTP server and has a web
imapfilter
Mail ServersScriptable IMAP mail filtering utility
Replaces Gmail filters
notmuch
Mail ServersFast, tag-based email indexing and search system
Replaces Gmail search
meli
Mail ServersTerminal email client with a modern interface
Replaces Mutt, NeoMutt
Sieve Editor
Mail ServersGraphical editor for Sieve mail filtering scripts
Replaces Gmail filters
phpList
Mail ServersNewsletter and email marketing with advanced management
alot
Mail ServersTerminal-based mail user agent for notmuch
Replaces Mutt
alps
Mail ServersSimple and extensible web-based email client
Replaces Gmail
Lieer
Mail ServersSync Gmail with a local notmuch mail database
Replaces Gmail web interface
Cyrus IMAP
Mail ServersScalable IMAP and POP server for large deployments
Replaces Microsoft Exchange
OfflineIMAP
Mail ServersSynchronize IMAP mailboxes to local Maildir
Replaces Outlook offline mode
OpenSMTPD
Mail ServersSecure and simple SMTP server from OpenBSD
Replaces Sendmail, Postfix
Postfix
Mail ServersFast, secure and reliable mail transfer agent
Replaces Microsoft Exchange
ViMbAdmin
Mail ServersWeb interface for managing virtual mail domains
Replaces cPanel email
isync
Mail ServersIMAP and Maildir mailbox synchronizer
Replaces Outlook offline mode
Apache SpamAssassin
Mail ServersRule-based and Bayesian anti-spam mail filter
Replaces Proprietary spam filtering appliances
afew
Mail ServersInitial tagging script for the notmuch mailer
Replaces Gmail filters
Sympa
Mail ServersScalable mailing list management software
Replaces Google Groups
Simple NixOS Mailserver
Mail ServersComplete mailserver solution leveraging the Nix Ecosystem
msmtp
Mail ServersLightweight SMTP client for sending mail
Replaces Sendmail
fdm
Mail ServersFetch and filter mail with a single configuration
Replaces fetchmail, procmail
DragonFly Mail Agent
Mail ServersTiny mail transfer agent for outbound delivery
Replaces Sendmail, Postfix
HyperKitty
Mail ServersWeb archive interface for Mailman 3 mailing lists
Replaces Google Groups
Postorius
Mail ServersWeb administration interface for Mailman 3
Replaces Google Groups
piler
Mail ServersEmail archiving system with full-text search
Replaces Mimecast, Barracuda Archiver
Claws Mail
Mail ServersLightweight and fast GTK email client
Replaces Microsoft Outlook
Fetchmail
Mail ServersRemote mail retrieval and forwarding utility
Replaces Gmail import
Nullmailer
Mail ServersSimple relay-only mail transfer agent
Replaces Sendmail
getmail6
Mail ServersFlexible mail retrieval tool for POP3 and IMAP
Replaces fetchmail
OpenDMARC
Mail ServersDMARC policy enforcement filter for mail servers
Replaces Proprietary DMARC services
OpenDKIM
Mail ServersDKIM signing and verification filter for mail servers
Replaces Proprietary email security gateways
Schleuder
Mail ServersEncrypting mailing list manager with OpenPGP
Replaces Google Groups
bogofilter
Mail ServersFast Bayesian spam filter for mail systems
Replaces Proprietary spam gateways
Dovecot Pigeonhole
Mail ServersSieve mail filtering engine for Dovecot
Replaces Gmail filters
DKIMpy Milter
Mail ServersDKIM signing and verification milter for mail servers
Replaces Hosted email authentication
mpop
Mail ServersSmall POP3 client for retrieving mail
Replaces fetchmail
Courier Mail Server
Mail ServersIntegrated mail server with IMAP, POP, and webmail
Replaces Microsoft Exchange
Afterlogic DAV
Mail ServersCalDAV and CardDAV server for Afterlogic WebMail
Replaces Microsoft Exchange Web Access
Dovel
Mail ServersSMTP server that sends and receives emails according to a simple
b1gMail
Mail ServersComplete email solution that runs on any webspace with PHP and MariaDB
Inboxen
Mail ServersLets you have an infinite number of unique inboxes
SquirrelMail
Mail ServersAnother browser-based IMAP client
EmailRelay
Mail ServersA small and easy to configure SMTP and POP3 server for Windows
Sendy
Mail ServersSelf-hosted email newsletter application that lets you send bulk
Sendmail
Mail ServersMessage transfer agent (MTA)
No apps match these filters.
At a glance
| App | Deploy effort | Difficulty | Min. RAM | License | ★ Stars |
|---|---|---|---|---|---|
| Mailspring | Read-the-docs project | Easy | 512 MB | GPL-3.0 | 17,909 |
| MailHog | Under-an-hour setup | Easy | 64 MB | MIT | 16,184 |
| Mail-in-a-Box | ≈5-minute setup | Easy | 1,024 MB | CC0-1.0 | 15,438 |
| Mailpit | Under-an-hour setup | Easy | 64 MB | MIT | 10,636 |
| Himalaya | Read-the-docs project | Medium | 64 MB | MIT | 7,436 |
| SimpleLogin | Under-an-hour setup | Medium | 512 MB | MIT | 7,049 |
| MailCatcher | Under-an-hour setup | Easy | 128 MB | MIT | 6,778 |
| AnonAddy | Under-an-hour setup | Medium | 512 MB | MIT | 4,896 |
| imapsync | Read-the-docs project | Medium | 64 MB | GPL-3.0 | 4,176 |
| smtp4dev | Under-an-hour setup | Easy | 128 MB | GPL-3.0 | 3,998 |
Quick picks
- Most adopted: Mailspring (17,909 GitHub stars).
- Lightest footprint: swaks (from 16 MB RAM, against 4,096 MB for the heaviest here).
- Fastest to deploy: Mail-in-a-Box (one-click platform packages).
- Licensing: 23 of 71 use GPL-3.0; check the rest individually if you plan to modify and redistribute.
Every option here is open-source and self-hostable, tagged Free within the mail servers category. Deploy effort is graded from published container recipes, not vendor claims — see the methodology.