If you create a filter with the rule From + isn't in my address book + <choose an address book>, does that work?

That only appears to work by specifying the entire email address. There isn't a way to enter a domain name (without the user name attached) in the address book, as far as I know.

I am not aware of any "known" domain filtering options specifically. Perhaps oyu could use javascript and the filtaquilla addonhttps://addons.thunderbird.net/en-US/thunderbird/addon/filtaquilla/ to emulate this. Personally I really can not understand what purpose it would serve or a use case where it would be useful. Giving a sender a free into your email lists because they share a gmail address with half the worlds population really does not sound helpful to me.

Matt, Thanks for the comments. I may try the addon. The purpose is as follows. I receive a large volume of email daily. More than half of it is spam or other unwanted email. I wish to sort known senders from unknown senders by their domains. Known senders may include colleagues from various institutions. I may not personally know them or their email address. However, I can identify their institution, company, or affiliation and respond accordingly. Garbage would be sorted into unknown senders and dealt with expeditiously. Thanks again.

Does the term various institutions imply say EDU domains? They would be reasonably simple to filter by using a email address contains .EDU filter. It might not be 100%, but It would be close I think.

Certainly, EDU, ORG, and GOV are included in my list, but they are easy to filter. I am far more concerned with corporate emails that use COM as do many spammers.