1.stalwartlabs / stalwart
All-in-one Mail & Collaboration server. Secure, scalable and fluent in every protocol (IMAP, JMAP, SMTP, CalDAV, CardDAV, WebDAV).
+328 stars
from 15,297 · score 5.80
Trending repositories
Ranked by Attention Score: stars gained over the last 7 complete days
8 repositories by Attention Score · Oct 27, 2026 – Nov 2, 2026 (UTC)
2.flectar / mail
Built from the ground up for speed. Flectar Mail delivers native performance, instant startup, and as little as 80 MB of RAM.
+109 stars
from 1,616 · score 4.70
3.Kozea / Radicale
A simple CalDAV (calendar) and CardDAV (contact) server.
+27 stars
from 5,143 · score 3.33
4.alainm23 / planify
Task manager with Todoist, Nextcloud & CalDAV support designed for GNOME
+16 stars
from 5,766 · score 2.83
5.pbek / QOwnNotes
QOwnNotes is a plain-text file notepad and todo-list manager with Markdown support and Nextcloud / ownCloud integration.
+11 stars
from 5,928 · score 2.48
6.ridafkih / keeper.sh
Calendar sync tool & universal calendar MCP server. Aggregate, sync and control calendars on Google, Outlook, Office 365, iCloud, CalDAV or ICS.
+9 stars
from 1,421 · score 2.30
7.jelmer / xandikos
A CalDAV/CardDAV server backed by Git
+3 stars
from 610 · score 1.39
8.mguessan / davmail
DavMail POP/IMAP/SMTP/CalDAV/CardDAV/LDAP Exchange and Office 365 Gateway - Synced with main subversion repository at
+1 stars
from 773 · score 0.69