Error: Your Microsoft Exchange server is unavailable

[1RobDog1]

The email client is outlook97.  We get this message on about 2 to 3 of our computers in our network of about 500 + PCs.  Two of which our at an offsite location behind a routor.  This error gets resolved by changing the frame type to 802.3 instead of auto on win95 machine.  But they can only send three lines of text and it is dog slow.  If we change it to 802.2 then TPS works otherwise it does not on 802.3.  We are a novell 4.x shop.  By default the frame type is 802.2 for novell 4.x.  This is where we want to be.  We changed the exchange server from 802.2 to 802.3 and 802.2.  Once we did it worked until we rebooted it over the weekend.  The only reason we are looking at frame types is because we get results when we change them.  Are we heading in the right direction on this can somoeone help whom has seen this or has suggestions.  Reply back if you need more info.  TIA...