Use from/ends with/twitter.com

"Begins with" can be used to filter just the local part of email addresses, i.e. the bit to the left of the @.

"Contains" will filter on the target string found anywhere within an email address, so could be used for your twitter filter as well. But "ends with" is more precise.

I suspect the star or asterisk (*) is a legitimate character in an email address, so could not easily be used as a filter wildcard. You'd have to use some trickery to get Thunderbird to understand if you meant a star as opposed to it representing any sequence of characters.

There is a powerful pattern matching mechanism called regular expressions that uses a dot to indicate any character. So if you actually want to detect a dot, and nothing else, you'd have to "escape" the dot to cancel out its special meaning. So your search term would use the syntax \. to indicate a literal dot. Note that Thunderbird doesn't inherently offer regular expression pattern matching, so this talk about regular expressions is intended merely as an illustration of the problem with the asterisk.

So you can see that if we were to use an asterisk in a filter string, we would need a similar trick to allow literal asterisks to be found. "Ends with", "Contains" and "Begins with" are, to my mind, elegant ways around this conundrum.

If you think you might have a use for regular expressions in Thunderbird's filters and searches, you can add these to Thunderbird via two add-ons:

FiltaQuilla Expression Search.