This article provides step-by-step instructions for downloading and installing a Digital Certificate onto your iPhone. If this is not the solution you are looking for, please search for your solution in the search bar above.
You can watch the following video for a tutorial.
How to Install a Digital Certificate onto your Apple iPhone :
After or When you downloaded your certificate from you PC, you may export it and sent it from your email along with the Intermediate and Root Certificate
How to use it :
> When you create an email no need to select anything, just write your message and hit Send.
> If everything was done correctly, look at your sent email and you will see a blue tick.
> Click the blue check and you can view the certificate and see it's trusted.
Check your certificate installation for SSL issues and vulnerabilities.