“connection to the server is offline” when all other network functions work normally.

When connected to a public network, my outlook 2010 will often not send my outgoing email due to "connection to the server is offline."  All other network functions seem fine.  Once I return to a known network, Outlook returns to normal function.  I can't wait until I return home from a business trip for my email program to work properly.  Anyone have a fix for this, other than risking calling  a public network a work network?

Thanks in advance,