Mac Mail freezing with repeated 'could not be moved' errors

I am running Mac OS 15.6.1 (Sequoia) pm a Mac Mini M-4 Pro with 48 gB of Ram and 1 tB internal SSD. My Mac Mail has been corrupted with mailware which essentially locks the program with repeated pop up message blocks with the message that reads: "The Message XXX couod not be moved to the mailbox Biz IMAP

Clicking OK closes the box, another box pops up immediately with another message name. This goes on and on as long as you close one another opens. No other function in MAIL can be selected. the only way to close is to Force Quit.