STYLETHREAD -- LET'S TALK SHOP!

um, creepy!

here's what I would do:

settings>filters>create a new filter

in the "from" field enter creepy uncle's address and hit "next step"

select "apply the label" and from the drop down select "new label" and call it "BLOCKED"

select "forward to" and enter creepy uncles address in the email address field.

That's the best solution I could come up with. Doesn't technically block him, but let's him think he's blocked. I would create a test filter with one of your email accounts before it's put in place too, just so you see how it appears.

hth!