A couple of years ago I was being pestered by a particular individual, the novelty of which had worn pretty thin.
This led to me setting the rules in my Mail for Mac so that any emails received from that individual's email addy would be automatically deleted.
This appeared to have worked. Until last night, when I received an email from the individual concerned.
I've checked the rule. It is still there, and is still 'active'.
How can this be?