Compare software

notmuch vs mu: catalog facts
notmuch	mu
Free Free to download and use.	Free Free to download, with source code on GitHub.
Command line	Linux, Command line
Fast global search across very large mail archives Tag-based organisation instead of folders	Fast indexing and detailed search of Maildir mail mu4e gives a full email client inside Emacs
Not a complete mail client on its own; needs a front end and a way to fetch mail Suited to terminal and editor users rather than beginners	Works only with Maildir storage; mail must be fetched separately The client side requires Emacs
Downloadable app	Downloadable app
Open source	Open source
License not stated	License not stated
No account needed	No account needed
Works offline	Works offline
Official website Full listing and sources Checked September 23, 2026	Official website Full listing and sources Checked September 23, 2026

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