Do kindly share...
Sent from mTalk on 950XL
This is what i Did.
I had several devices with same Microsoft account with sync of windows settings between devices turned on. In one of those devices notification from Mail app was turned off. So I enabled notification from Mail app in that device. Also made sure that under apps allowed in background, Calendar app was toggled on, Because Calendar and Mail app works as one.
But that didn't solved the problem.
In my PC where I was having the problem, under Settings>System>Notifications & Actions, Mail app was not listed. So couldn't check if that was turned on/off.
My mail app actually had only one email account (G-mail) added to it. So to find out whether I can receive notification from another email account (Outlook) , I added the second mail account in the Mail App. Then I tried sending a Mail from Gmail to Outlook,from the mail app itself and waited for Notification.
That Worked.
Then i rechecked the Settings>System>Notifications & Actions and found that Mail App was listed.
Seems like adding a second email account solved the problem. Or you might try deleting the current email account from the app and adding it again.
Also make sure that Mail and Calendar app is updated to latest version.