None that I know of that are smart enough to work out where you are.
You could use Switch Identity within Entourage to create two different settings, one for home, one for work. See as they are Exchange/IMAP accounts you wont lose any emails as each account will just sync when connected.
Otherwise turn off the error noise and close the error pop up once and it shouldn't reappear on each failed send and receive. That's what I do.
If they want you to check your work IMAP emails at home tell them to allow you to, you could get a VPN setup if they are worried about security.