how create filter to exclude content text string?

[~A_Sammy]

Hi,
Lately I've been gettig spammed by mortgage lenders and they never have the
word mortgage in the header. I can't figure out how to make a filter that
checks the body of an email. If I could, I could make it send those
containing the word "mortgage" to the junk email bin.
Can anybody tell me if that's possible, and if so, how to do it?

Thanks,
Sammy