what email client are you using?
 
POP? IMAP?
 
check your OUTGOING mail server settings.
 
you mentioned a server@ work.this server handles your email functions? domain names, etc?
 
can you use a webmail client to send OK?

Welp..spent an hour or so on the phone with a guy from our ISP.  He took over my computer and tried a bunch of stuff to no avail.  Then he passed me over to another guy who started to work on it but accidentally disconnected us.  Screw it, said I.  But he must've done something right cause when I got back from lunch...Yippie!...we were working again.  Bet I have a new IP address too.

I should have said it can take up to 24 hours for blacklist removals to propagate around the net...

Glad you're up and running again.