Cannot Send Mail in Outlook 2007 - Error 0x80042109

I cannot send email from Outlook. I get an error 0x80042109. I am running
Outlook 2007 SP2 under Vista Ultimate SP2.

I am writing an application in VS2008 that required that I install a client
certificate from a Federal agency. When I connect to the agency secure site
with IE8 it complains about the certificate. I have not been able to send
mail since installing the certificate. I uninstalled the certificate but the
trouble continues.

I deleted my and recreated my email account and the trouble continues. I
can authenticate and receive mail OK but I cannot send.

I would greatly appreciate any input or solution.

Thanks,
Eagle