I patched the install.rdf-file of version 22.214.171.124 so that it is possible to install attachment extractor to a Thunderbird up to version 99 without version-error. Tested with TB 38.0.1, but no warranty for functionality. Available on my homepage dvschuetz.de under "Anleitungen - Email - Thunderbird Add-Ons".
Working for me (Win XP pro SP3, TB 3.1.6, 3.1.7..., POP, IMAP). Only when using auto-extract on IMAP-Folders I sometimes get the problem that the message is duplicated afterwards: one time with the attachment, one time without.
This review is for a previous version of the add-on (1.3.5).