Larch 1.1.0 released

Version 1.1.0 of Larch is now available.

Larch is a command line tool for copying email quickly and reliably from one IMAP server to another. It’s smart enough not to copy messages that already exist on the destination server, robust enough to pick up where it left off when interrupted, and also capable of more advanced operations like syncing message flags from the source server to the destination server. Larch is particularly well-suited for copying messages to, from, and between Gmail and Google Apps accounts.


Larch is a Ruby application and requires Ruby 1.8.6 or higher (1.9.2 is recommended). Once Ruby is installed, install or upgrade Larch via RubyGems:

gem install larch

What’s new

This release is the culmination of over a year of bug fixes and feature development. Larch is now faster and more reliable than ever. The most significant new features are:

  • Mailbox and message state information is now stored in a local SQLite database, which allows Larch to resync and resume interrupted operations much more quickly without having to rescan all messages.
  • You can now provide configuration options via a config file, so you don’t need to pass all options on the command line. This also allows the use of named session configs, so running larch gmail-to-yahoo will use the config options defined under the gmail-to-yahoo section in the config file.
  • Yahoo! Mail IMAP is now supported when connecting to or, even for non-pro accounts. Note that Yahoo! doesn’t officially support the use of IMAP by non-pro accounts, so this feature should be considered experimental.
  • Performance and reliability have been improved significantly. Many bugs have been fixed and many workarounds have been added for misbehaving servers.

This is only a partial list of changes. For the complete list, see the HISTORY file. For more details on how to use Larch’s new features, see the comprehensive README.

Try it out, report bugs

Please use Larch’s GitHub issue tracker to report bugs and request features. If you have questions or need help with Larch, the first thing you should do is read the very detailed documentation. If that fails, search the archives of the Larch mailing list on Google Groups. If you still can’t find an answer, send your question to the list.