filelink provider for firefox send
Mozilla launched the https://send.firefox.com/ service some time ago. A great service to securely share (big) files. Thunderbird has the filelink feature for quite a while, allow attachments to be uploaded to some storage, replacing the attachment in the email by a link.
Now it would be pretty logical, that there is a filelink provider, that uses firefox send as backend. But this does not exist. Why?
Wšě wotmołwy (1)
Perhaps no one has filed an enhancement bug to request it. Given Thunderbird in NOT a mozilla product anymore expectations of tight integration with Mozilla products are probably not going to be met.
You might file a bug here. https://bugzilla.mozilla.org/home