I had a godaddy cert and a self signed they both were expired and I still was able to get email in Outlook 2010 and also my Iphone. This morning I deleted the 2 expired ones and then created a new self signed cert. I exported the cert and installed it on my computer and no longer get the warning in Outlook when I open. But now my iphone doesn't work. I deleted the account and tried to setup an new one but it is unable to verify account.
I sent the cert to another email account on my phone and I installed it but that still doesn't work. So maybe I need to create a different or speical type of cert for my iphone?