You might well be familiar with some or all of this, but here’s some background on spam and spam filtering...
Is this the same exact sender, using the same email address? If so, then the filtering rules can and should work. View the full headers of a filtered message, and view the headers of a not-filtered mail message that you believe should have been filtered. If all of the details of both of messages match what’s in the filters then—as Eric Root sagely notes—there’s probably another filtering rule that’s interrupting and blocking the processing of the desired rule.
If this is not the same sender and not the same email address—which comprises the vast majority of spam, unfortunately—client-side address-based email rules are futile. Why? The spammers can and routinely do vary the sending email address, subject line, and many other details of the message. And rarely if ever re-use these details. This to bypass filtering rules.
Using client-side filtering, you cannot block spam before it enters your inbox. The filters only work on arriving mail, and while those filters might quickly flag or file away or delete that arriving mail depending on the local rules, the email messages have to arrive at the client in order to be filtered, scanned and otherwise processed.
Server-side filtering can block spam before the message arrives in your inbox, but you’re not using those capabilities here, and not all email providers even provide access to customize server-side spam filtering. Server-side filtering can drop or can block spam arriving at the mail server, before those messages are then transferred into the recipient’s inbox.
If you’re interested in better spam filtering, one of the techniques used is called Bayesian Filtering, which looks not at the always-varying sender data, and at spam filtering that looks at the contents, construction and phrasing of the spam, as well as matching against copies of the spam from other recipients. Bayesian filtering is a statistical technique, seeing to determine whether the arriving mail message is spam or not, based on many factors associated both with spam and with legitimate mail arriving in your inbox.
One add-on client-side spam-filtering option that works well on macOS is SpamSieve. There are likely others. I’ve had good success with spam filtering, using SpamSieve.
lf your email provider offers access into Spamassassin or some other server-side filtering tool, that too can reduce the amount of spam arriving.
