Yes in this business rule you can put in script to abort if the only recipient is this specific email address otherwise it can update the recipient list using the replace():
BR Condition - recipients contains BAD-EMAIL-ADDRESS
Script:
//Abort of only recipient is bad email address
if (current.recipients == "BAD-EMAIL-ADDRESS") {
current.setAbortAction(true);
} else {
//Find the bad email address and remove it
var emailRecipients = current.recipients.toString().split(",");
var emailIndex = emailRecipients.indexOf("BAD-EMAIL-ADDRESS");
emailRecipients.splice(emailIndex, 1);
current.recipients = emailRecipients.join(",");
}
