Indispensable Rated 5 out of 5 stars
I think this is an absolutely great, and for me, indispensable addon.
All my business email is organized into folders and sub-folders based on activity and company.
Example: I have a Sales folder, under which are folders for Industrial, Government, Dealers, etc. Then there are further sub-folders for each company.
Also, I need to store email for years for historical and legal reasons.
Having all outgoing mail dumped into a generic Sent folder does not work when trying to find an old email.
With hundreds of folders to track this addon is absolutely necessary.
Since the current version of this addon does not work with Thunderbird 3.1.x I have edited the <em:maxVersion> in the install.rdf (part of the xpi file) to read 3.1.8.
This has saved me in the past with other addons for Firefox and Thunderbird until the author provides an official update, though it doesn't always work.