OE is not resolving Email addresses

[KingofSketch]

Hiya guys
I got quite a strange problem with Outlook Express 6,
I can only send emails to people who have emailed me, any other addresses i try it comes up saying that the address is not recognised,

I have checked my dns servers and they are all ok

so i'm a bit stumped! Sketch
"Eagles may soar, but weasels don't get sucked into jet engines"

 

[smah]

Corrupt address book maybe? Try adding a new address to your address book & then send to it.

 

[KingofSketch]

I'm afraid not, as its happening on more than one machine Sketch
"Eagles may soar, but weasels don't get sucked into jet engines"