Open source alternatives to Outlook

One project on starwire does the same job. Ranked by how much of what Outlook does each one covers, read from its README and website. Ties go to the most active.

What Outlook does

Emailcore
Calendarcore
Contacts
Meeting scheduling
Multiple accounts
Search and rules
Desktop, mobile and web apps

Each dot in the table is one job, in this order. Square dots are core jobs and count double. Full means yes, half means partly. "See the evidence" under a project shows the line behind each one. Coverage is what a project documents, not how well it works or how hard it is to move to. How we score this

Project	Covers	Stars	Commits, 12 weeks	Last release	Closed vs opened	Setup	License
mailNative cross-platform mail, calendar and contacts client with low idle memory	Replaces it78%	1.9k+88	1,287	37 days ago	65%	Install like an app	AGPL-3.0
Covers all 2 core jobs. Partly: Search and rules; Desktop, mobile and web apps. Not shown: Meeting scheduling.See the evidence EmailcoreYesa lightweight, native home for your email, calendars, and contacts CalendarcoreYesCalDAV-backed calendar sync ContactsYesMove between mail, calendars, and contacts Meeting schedulingNot shownNeither the README nor the website mentions it. Multiple accountsYesGroups accounts into profiles such as Work or Personal Search and rulesPartlyattachment search, offline files and previews Desktop, mobile and web appsPartlytouch-friendly compact interface

Vital signs from GitHub, checked weekly. How we read these · How setup is read

All repos

Sort

Form Platform Works with Theme License Setup Language

New repos every two days, stars refreshed daily. Visits are counted without cookies, and the numbers are public. How it works Data RSS Newsletter