Top 6 Open-Source Alternatives to Knowmail

Product categories

Calendar Disposable Email Email Email Archiving Email Clients Email Management Email Security Email Service Provider Enterprise Communication SMTP Server Self-hosted Email Website Builder

Summary

The top open-source alternatives to Knowmail are Mail-in-a-box, Mailpile, and Spark Mail. 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.

Mail-in-a-box Landing Page
1

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
Mailpile Landing Page
2

Mailpile

Mailpile is a modern, fast web-mail client with user-friendly encryption and privacy features.
Pricing:
- Open Source
#Email #Email Clients #Email Management
Spark Mail Landing Page
3

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
Mailspring Landing Page
4

Mailspring

Mailspring is a mail client for Mac, Windows and Linux.
Pricing:
- Open Source
#Email #Email Clients #Calendar 25 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
Thexyz Landing Page
6

Thexyz

Secure premium email service with mobile sync apps for calendar, contacts, tasks, notes and FISMA compliant email archiving.
Pricing:
- Open Source
- Paid
- $2.95 / Monthly (25GB)
#Email #Email Security #Email Archiving 1 social mentions