>Our network admin says he would prefer I used a control that makes use of SMTP directly to avoid the overhead associated with the MSMAPI control.

I doubt thats a valid concern, but thats just my opinion.

>If so where can I find a control that makes use of SMTP directly without requiring that a mail client be installed for each session that runs under Citrix.

I think wwIPStuff does this, http://www.west-wind.com/wwIpstuff.asp