OS X 10.10 Apple Mail not recognizing S/MIME certificate

Question

After upgrading to Yosemite, Apple Mail no longer recognizes my S/MIME certificate. This was working in Mavericks. I've checked Keychain and the certificate is valid, even evaluated it as S/MIME for my email address and it passed. However, emails I send do not contain the certificate and I cannot figure out any way in Apple Mail to sign them.

I've read Apple's help article and it says an icon should display next to the From: field on new emails. However, I only use a single account with Apple Mail, so the From: field doesn't display. If I do add another account, just so that field displays, no signing icon is shown when I create a new email.

Any help would be greatly appreciated.

Solution

I solved this problem by selecting my private key under my certificate (issued by Comodo) and in the get info window:access control tab deleting Mail.app from the "Always allow access..." list and adding it back immediately. When I saved the changes (to the keychain) and opened Mail, I was able to sign my messages again.

Comments

[Rebecca Dessonville]

I had this issue last week, fixed it for a day (by resetting mail), but now two days later it won't recognize my cert again. I'm having the same issue with a valid comodo certificate.

[Rebecca Dessonville]

I was successfully able to send signed emails as a reply to a signed email assuming I hadn't tried to send a new signed email in the open session of mail: 1. Start Mail 2. Try to send new signed email 2-results: fail 3. Try to reply to a signed mail with a signed mail 3-results: fail 4. Restart mail 5. Try to reply to a signed mail with a signed mail 5-results: successful 6. Try to send a new signed email 6-results: failed 7. Try to reply to signed mail from step 5 with a signed mail 7-results: fail

[Jonathan Freeland]

@Dez When you say "resetting mail", what do you mean? I'll give that shot. Ironically, the upgrade worked fine on my Hackintosh, but not my MacBook.

[Rebecca Dessonville]

Sorry... I meant to quit and reopen mail. I'll update my comment... and I can't update it... nevermind. That's what I meant.

[Rebecca Dessonville]

Also found that I can't read email encrypted with my certificate unless I exit/open the mail app