Yes but I can’t search by the name of the attachment.
I just searched for text thats in an attachment filename and it worked - with a caveat. I have a filename called “PMASUP236 - Operate Vehicles In The Field.pdf” on an email. There is no reference to the PMASUP236 in any other part of any email.
If I search “PMASUP236”, it returns the email as a result.
If I search “SUP236” it does not.
If I search “Operate Vehicles” it returns that email (along with a heap of others containing the word “Operate” and “Vehicles” in any order).
Admittedly this is on Windows at work, though I do run Thunderbird on Linux at home. Will have to try it there to confirm.
I just checked on Linux (Thunderbird 128.5.2esr, Opensuse Tumbleweed) and the behaviour is the same.
This is using the normal search function (top of screen in current version). Quick Filter does not look at attachments at all by the looks. The “Attachments” toggle is only a has / does not have attachment filter.