Not able to choose Email Account created using Microsoft Intune

I have 3 mail accounts 2 are private emails and another Email account is created through Microsoft Intune(MDM solution).

If I set the Email account which is created through Microsoft Intune as standard I am only allowed to send from the Email account which is created through Microsoft Intune. No other options. If I set one of the other two emails as standard I am not allowed to send from Email account which is created through Microsoft Intune.

Regards,
Arjun