Filter Sender - Contains

Filter Sender - Contains

Hi.  I have been able to get SENDER filters working using "IS" and an exact match on an email address.
I was not able to do any other partial match filters, however.

SENDER  IS   a@b.com       works
SENDER  CONTAINS b.com   does not work for me
SENDER  ENDS WITH b.com  does not work for me


I saw some similar forum posts, but nothing exactly like mine.  Is this a known problem?


thanks
Brian