Secure Email Certificate

I have been trying to digital sign outgoing email but it won't let me, why, just curious, thanks for any respond.

Hello,
Please read this guide for certificate:

http://runasxp.com/Thread-SOLVED-Digital-ID-s

thanks

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followed the directions from thread, certificate is install but can't send mail signed but when i click to unsign then it will send. don't know whats the problem.