Poco Junk Mail FAQ - Detecting spammers usurping my address

Q: I receive loads of Spam which has the first part of the EMail address (beofre the @) as the same as mine but the domain varies, I want to be able to tell Poco to delete any mail from any sender starting with the same as my account except where it is my email address.
 
A: Create a new filter, in the first condition element put:
Search: From
For: gjblackford
Change the "then" drop down to "and"
Search: X-Mailer
For: Poco
Check the "Match only if not found" box
Change the "then" drop down to "and"
Search: From
For: %addressbooks%
Check the "Match only if not found" box
Action: Increase junk score
Action: Move message to "Junk Mail" (or delete if and when you are comfortable with that).