Just for the information of anyone, I found out how to do it...
Off course qmail is the piece of code responsible for handling mails in e-smith 5. and IMP simply is the front-end if you would.
In order to have qmail use an alternate SMTP server for sending out mails, the following file need to be changed:
/var/qmail/control/smtproutes
Simply add the following line to the end of the file:
:my.smtp.server.to.use
Replace "my.smtp.server.to.use" by your provider smtp server, in my case Sympatico's smtp1.qc.sympatico.ca
Off course if you want to make that change permanent, you need to change the corresponding template and expand it.
Hope this helps peoples

Andre Courchesne
www.net-forces.com