Mail junks messages from known senders

[bbell2000]

I have an iMac and a MacBook Pro. Mail is configured exactly the same on both. Specifically:

1) Under Preferences->Junk->Exempt: the "Sender of message is in my Address Book" is checked.
2) There are no Rules other than the default.

Junk filtering works well on the MacBook Pro (a newer install that has been "learning" for a month or two. The iMac on the other hand insists on moving messages from known senders to the Junk folder. By known sender, I mean addresses that are in my address book. The iMac is 2 years old so I'm assuming it has "learned" much more about junk mail than the MacBook.

Can anyone give me suggestions as to how I can fix this? I'd be willing to reset the junk history on the iMac if someone can tell me how.

Both systems are running up-to-date Leopard.

Thanks.

 

[MisterMe]

It appears that you have tried to program the virus filter. Reset the filter. Put it back in training mode. Train it by example only.

 

[bbell2000]

It appears that you have tried to program the virus filter. Reset the filter. Put it back in training mode. Train it by example only.

Are you referring to the Advanced setup on the Junk tab? If so, then yes... I tried to configure the filter to move message to junk if and only if all of the following are true:

Sender is not in my address book
Sender is not in my previous recipients
Message is not addressed to my full name
Message is junk mail.

If that's not what you're referring to, please elaborate. I can't find anything in Mail Preferences referring to a "virus filter" and therefore have no idea how I'm supposed to reset it.