Developer reply by Sancus
Rated 1 out of 5 stars
C'mon Guys,
On YOUR website you feature "FileLink provider for WebDAV" as a provider for linking attachments, then won't let me install it because it's unsigned. Let's get our act together here.
Thunderbird add-ons do not require signing. Install this by searching for it in the Add-ons Manager in Thunderbird and it installs with no trouble on 91.*
To create your own collections, you must have a Mozilla Add-ons account.