Mailspring
Mail ServersCross-platform desktop email client
Replaces Outlook, Apple Mail
Best Cross-Platform Mail Servers for self-hosting
The 30 best Cross-Platform mail servers you can self-host, ranked by community traction.
Roundcube
Mail ServersBrowser-based IMAP webmail client
Replaces Gmail, Outlook Web
Himalaya
Mail ServersModern command-line email client written in Rust
Replaces Mutt, Outlook
imapsync
Mail ServersSynchronization and migration tool between IMAP accounts
Replaces IMAP migration services
NeoMutt
Mail ServersFeature-rich terminal email client
Replaces Microsoft Outlook
aerc
Mail ServersEfficient terminal-based email client
Replaces Gmail, Outlook
DebOps
Mail ServersYour Debian-based data center in a box
Betterbird
Mail ServersCommunity-enhanced fork of the Thunderbird email client
Replaces Microsoft Outlook
imapfilter
Mail ServersScriptable IMAP mail filtering utility
Replaces Gmail filters
notmuch
Mail ServersFast, tag-based email indexing and search system
Replaces Gmail search
Sieve Editor
Mail ServersGraphical editor for Sieve mail filtering scripts
Replaces Gmail filters
meli
Mail ServersTerminal email client with a modern interface
Replaces Mutt, NeoMutt
phpList
Mail ServersNewsletter and email marketing with advanced management of
Lieer
Mail ServersSync Gmail with a local notmuch mail database
Replaces Gmail web interface
OfflineIMAP
Mail ServersSynchronize IMAP mailboxes to local Maildir
Replaces Outlook offline mode
isync
Mail ServersIMAP and Maildir mailbox synchronizer
Replaces Outlook offline mode
Afterlogic WebMail Lite
Mail ServersFree webmail front-end for IMAP and SMTP servers
Replaces Gmail, Outlook Web
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
Claws Mail
Mail ServersLightweight and fast GTK email client
Replaces Microsoft Outlook
getmail6
Mail ServersFlexible mail retrieval tool for POP3 and IMAP
Replaces fetchmail
mpop
Mail ServersSmall POP3 client for retrieving mail
Replaces fetchmail
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 and
Sendy
Mail ServersSelf-hosted email newsletter application that lets you send bulk
Sendmail
Mail ServersMessage transfer agent (MTA)
No apps match these filters.
Every option here is open-source and self-hostable, tagged Cross-Platform within the mail servers category. Compare them on the individual app pages for setup difficulty and resource requirements.