Save accepted untrusted certificates on email app (HTC Sensation)

I have a problem with the mail (not gmail) app on my HTC Sensation, that I'm guessing is part of HTC Sense 3. I'm using a server that has an untrusted certificate, and every time I try to refresh my email a dialog requesting the certificate to be accepted pops up. The problem is that when I try to send an email from that account the messages get stuck in the outbox until I manually refresh the mail forcing the certificate to be accepted again. Is there any way of storing the known/already-accepted certificates for the mail app? Thanks!