Top 11 Open-Source Alternatives to Microsoft Mail and Calendar

Product categories

Appointments and Scheduling Calendar Calendar And Scheduling Email Email Clients Email Management Encryption Enterprise Communication Hosted Email SMTP Server Security & Privacy Self-hosted Email

Summary

The top open-source alternatives to Microsoft Mail and Calendar are Spark Mail, Mailspring, and Simple Calendar. 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.

Spark Mail Landing Page
1

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
2

Mailspring

Mailspring is a mail client for Mac, Windows and Linux.
Pricing:
- Open Source
#Email #Email Clients #Calendar 25 social mentions
Simple Calendar Landing Page
3

Simple Calendar

A simple calendar with events (optional recurring and reminders), week numbers and a customizable...
Pricing:
- Open Source
#Calendar #Appointments and Scheduling #Email 99 social mentions
Nextcloud Mail Landing Page
4

Nextcloud Mail

💌 Mail app for Nextcloud
Pricing:
- Open Source
#Email #Email Clients #Enterprise Communication 5 social mentions
Nextcloud Calendar Landing Page
5

Nextcloud Calendar

The Calendar app is a user interface for Nextcloud's CalDAV server.
Pricing:
- Open Source
#Calendar #Appointments and Scheduling #Email 4 social mentions
FairEmail Landing Page
6

FairEmail

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

Tutanota

Get your encrypted mailbox for free.
Pricing:
- Open Source
#Email #Email Clients #Enterprise Communication 177 social mentions
Calendar Lock PEA Landing Page
8

Calendar Lock PEA

Calendar Lock PEA is an encrypted desktop calendar with a day, week and month view. The shown calendars are never stored unencrypted on your disk, but exist only in the RAM. Platform-independent, Open Source, no installation or registration required.
Pricing:
- Open Source
#Calendar #Appointments and Scheduling #Encryption
Mailpile Landing Page
9

Mailpile

Mailpile is a modern, fast web-mail client with user-friendly encryption and privacy features.
Pricing:
- Open Source
#Email #Email Clients #Email Management
Roundcube Landing Page
10

Roundcube

Web-based IMAP email client
Pricing:
- Open Source
#Email #Email Clients #SMTP Server 16 social mentions
iRedMail Landing Page
11

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