Apple Mail Rules and Spam

I have a smart mailbox where I move all mail sent to a yahoo address,
I receive “news” from Yahoo that is moved into referred mailbox.
I have not found a rule that will trash or delete just those messages. Some are messages labeled as Spam messages from the same sender that I cannot trash or delete with a rule.
I set Spamsieve to train as spam and stll nothing happens.
Any ideas?

I am running Catalina, SpamSierve 2.9.44. Mail 13.4
thank you

A smart mailbox does not move anything. It is just a set of saved search criteria.

Are the messages going to the Yahoo inbox or to another Yahoo mailbox? Mail only applies its rules to messages that arrive in the inbox.

It sounds like you are trying to delete all messages sent to this account, but why? Would it make more sense to close the account or remove it from Mail?