Compare software

WildDuck vs grommunio: catalog facts
WildDuck	grommunio
Free Free open-source software that you host yourself.	Freemium Open source, with paid plans listed on the pricing page.
Linux, Self-hosted	Linux, Web, Self-hosted
Horizontal scaling with no single point of failure Full IMAP4rev1 support with many extensions	Native MAPI, EWS and EAS support for Outlook and mobile clients Mail, calendars, chat, video and files on one platform
Needs MongoDB, Redis and separate SMTP components Aimed at large deployments rather than small personal servers	Running a groupware server requires administration skills Some features may depend on paid plans
Self-hosted	Self-hosted, Hosted service
Open source	Open source
License not stated	License not stated
Not stated if an account is needed	Not stated if an account is needed
Not stated if it works offline	Not stated if it works offline
Official website Full listing and sources Checked October 1, 2026	Official website Full listing and sources Checked October 1, 2026

Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.