Top 12 Open-Source Alternatives to Thunderbird

Product categories

Calendar Email Email Clients Email Management Email Service Provider Enterprise Communication Hosted Email Open Source SMTP Server Self-hosted Email

Summary

The top open-source alternatives to Thunderbird are Mailspring, Spark Mail, and Roundcube. One of the criteria for ordering this list is the number of mentions that products have on reliable external sources. You can suggest additional sources through the form here.

Mailspring Landing Page
1

Mailspring

Mailspring is a mail client for Mac, Windows and Linux.
Pricing:
- Open Source
#Email #Email Clients #Calendar 25 social mentions
Spark Mail Landing Page
2

Spark Mail

Spark helps you take your inbox under control. Instantly see what’s important and quickly clean up the rest. Spark for Teams allows you to create, discuss, and share email with your colleagues
Pricing:
- Open Source
#Email #Email Clients #Calendar 30 social mentions
Roundcube Landing Page
3

Roundcube

Web-based IMAP email client
Pricing:
- Open Source
#Email #SMTP Server #Email Clients 16 social mentions
Tutanota Landing Page
4

Tutanota

Get your encrypted mailbox for free.
Pricing:
- Open Source
#Email #Email Clients #Enterprise Communication 177 social mentions
iRedMail Landing Page
5

iRedMail

A fully fledged, free email server solution, an open source project (GPL v2).
Pricing:
- Open Source
#Email #SMTP Server #Self-hosted Email 2 social mentions
FairEmail Landing Page
6

FairEmail

Open source, privacy friendly email app
Pricing:
- Open Source
#Email #Email Clients #Calendar 52 social mentions
Mailpile Landing Page
7

Mailpile

Mailpile is a modern, fast web-mail client with user-friendly encryption and privacy features.
Pricing:
- Open Source
#Email #Email Clients #Email Management
Mail-in-a-box Landing Page
8

Mail-in-a-box

Mail-in-a-Box provides webmail and an IMAP/SMTP server for use with mobile devices and desktop mail software and also includes contacts and calendar synchronization.
Pricing:
- Open Source
#Email #Self-hosted Email #Email Service Provider 115 social mentions
Rainloop Landing Page
9

Rainloop

RainLoop is a web based email client.
Pricing:
- Open Source
#Email #Email Clients #Email Management
SOGo Landing Page
10

SOGo

SOGo is groupware server with a focus on scalability and open standards.
Pricing:
- Open Source
#Email #Email Clients #Self-hosted Email 1 social mentions
mailcow Landing Page
11

mailcow

An open source mailserver suite.
Pricing:
- Open Source
#Email #Self-hosted Email #Email Service Provider 82 social mentions
NeoMutt Landing Page
12

NeoMutt

NeoMutt is a command-line mail reader. It's a version of https://alternativeto.
Pricing:
- Open Source
#Email #Email Clients #Calendar 10 social mentions