If you have a Smart Phone and you have a POP3/SMTP email system using SSL, you may be required to download and install the SSL certificate on to your phone, before you can get email on your phone. You may not find this to be as easy as you want it to be.
Some Smart Phones require the SSL certificate to be in the “.cer” format. If you find yourself in this situation, the following command will allow you to convert the SSL certificate from “.pem” to “.cer” for use on your smart phone.
FYI: When converting the SSL certificate from .pem to a DER format, make sure you use the .cer extension!
test:~# openssl x509 -outform der -in ca.pem -out ca.cer
If you have questions about this process, you will have to contact the manufacturer of your Smart Phone and/or the Cellular Service Provider you subscribe to. Though, I doubt they will be much help.
Maybe try posting your issue in the comments section of this article.