Convergent builds its mail service on free software and sends its fixes upstream. Twelve pull requests accepted by SnappyMail and Tachyon: address book sync, message HTML sanitising, two-factor authentication, calendar invitations and LDAP directories.
Three Convergent fixes merged into Cyrus IMAP: a CalDAV server crash on free/busy requests, HTTP/2 responses truncated past 64 KB, and the version number still exposed in calendars despite serverinfo: off.
Consolidate several clamd instances into a single containerized ClamAV engine (Podman/Quadlet), non-root, exposed over a group-restricted unix socket, sharing the host's signatures — without wasting memory.