An application that supports it (Exchange Server) will query the MX records and test that the remote system is responding, if so it will send the e-mail. If not responding it will check the next available server in the list and so on until it either finds a server responding or not.

As an example, these servers all handle e-mail for you.

10 smtp.Gwspikval.Com
30 smtp.inet.fi
20 smtp.tele.fi

1st try goes to smtp.Gwspikval.Com
2nd try goes to smtp.tele.fi
3rd try goes to smtp.inet.fi


Edited by Jooel (2004-12-15 10:23 PM)