Compare software

isynclieer
Free

Free and open source under the GPL.

 Free

Free and open source under the GPL-3.0 or later.

Windows, macOS, Linux, Command line macOS, Linux, Command line
  • Much faster than Python-based synchronisers on large mailboxes
  • Precise control over which folders sync and in which direction
  • Two-way sync between Gmail labels and notmuch tags
  • Keeps a full local maildir copy of the mailbox
  • Configuration syntax is terse and mistakes can delete mail
  • Command line only
  • Only works with Gmail accounts
  • Requires notmuch and command-line setup
Downloadable app Downloadable app
Open source Open source
License: GPL-2.0 License: GPL-3.0-or-later
Not stated if an account is needed Account needed
Not stated if it works offline Works offline

Checked September 22, 2026

Checked October 1, 2026

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