Overview
From the last article, I hope you are now wondering “where do I get this awesome thing called S/MIME certificate!”, and the other kicker “What’s it going to cost me?” Well you are in luck because email certificates can be obtained for free! There are two site (that I know of) that provide free S/MIME email certificates: Instant SSL and Start SSL.
How To
For this How To, I’m going to use Instant SSL. I have nothing against StartSSL (in fact they also give out free one year SSL website certificates!), but I find Instant’s process simpler and more direct.
- Request your certificate by going to
- Click on the “Get it Free Now” button located in the top-middle section of the page.
- This will open a new page requesting general information such as name, your email which you want acquire an S/MIME certificate, key size (leave the default 2048), and a revoke key (if you feel your certificate has been compromised, this will allow InstantSSL to make your certificate invalid thus will generate a warning to anyone opening a message in the future).
Upon submitting your information, you should be forward to a page stating your “Application for Secure Email Certificate” is successful. Go check your email and wait for a message from InstantSSL (should be relatively quick), and click on the button that states “Click & Install Comodo Email Certificate”.- You should now have downloaded an encrypted CollectCCC.p7s file that contains both your Public and Private Key.
- Double click the CollectCCC.p7s file to import your S/MIME certificate into Keychain Access (it should be located in your “login” keychain if Keychain Access asks you where to save the file).
- To verify this has been done, locate your login keychain, select “My Certificates” and you should see your email address with a triangle to the left. click on the triangle and this will display your private key (with an icon of a key).

That is it! You now have a S/MIME certificate for signing and encrypting email messages. Stay tuned for using your newly acquired S/MIME email certificate in Apple Mail and in iOS.
Step One; Enter your name, email, key size, and revoke key
Step Two; Success! Now check your email
Step Three; Download, double-click and install in Keychain Access