Carmen,
Sorry I was unable to assist you yesterday. I am hoping it is not too late.
The FQHN that is needed is for your domino server. I need to know if you plan to send mail directly from your Domino server or to relay it through your ISP or your firewall?
Another thing you can do that I find quite helpful to troubleshoot these problems is to set the following notes.ini parameter smtpclientdebug=1
See the following link:
http://www-1.ibm.com/support/docview.wss?rs=203&q=smtp+client+debug&uid=swg27003007&loc=en_US&cs=utf-8&lang=en+en