In running a FROM message filter to CONTAIN the only the specific characters .com. [to be clear, I mean four (4) characters without quotes: ".com."] apparently, the 2nd "." is being ignored (and perhaps the 1st "." as well?). So all the com occurrences are processed, whether preceded by the "." or not (including ".com>" as well). I see in the exemplars that a full email address (xxxxx@yyyyy.zzz) is possible. I wondered whether certain characters are not permitted to follow certain others, or if there is a logical anomaly... I'm stumped. Advise soonest.

Win10 Home 22H2 OS Build 19045.4894 Thunderbird 128.2.3esr