How to connect an Exchange account with a self-signed ssl certificate on iOS 10.2?

Question

iOS

Good day.
I have an iphone updated to iOS 10.2.1. An Exchange account was connected and synchronized on the device: mail, calendar (especially important), contacts, etc.
To connect to Exchange, an SSL certificate issued from a self-signed certificate is used.
On previous versions of iOS (everything works on version 10.1), it was possible to continue when adding an Exchange account to an untrusted certificate message (now you can only cancel or read the details). Or it was possible to pre-download (for example, via mail) the certificate and install it in iOS (in the current version of iOS, there is no way to call the certificate installation dialog using standard tools).
On the device, use third-party software, jailbreak is not possible.
If anyone has encountered such a problem - write a solution.
Thank you in advance.

Answer 1

I did this: We
send a certificate to an iPhone (Any way).
Save to files.
We go into the files, install the certificate.
We go into the settings, main, about this device, certificate trust, put the switch in front of our certificate.
Set up an account.