I would like to setup a Gmail filter which deletes all messages from a specific known sender which are addressed to a couple of people at once, and not just me (but keep those messages addressed to just me). Is this possible? Something along the lines of:

[from:fredexample.com to:multiple]

You might be able to approximate that effect.

[from:fredexample.com to:(yahoo OR hotmail OR etc)]

Cool, that'll do, I will try that. Thanks!