Email notifications for @Mentions on Private Channel not working

ChrisWebbTech 

I have been working with Microsoft Support, but I wanted to share one of the suggestions that they have provided thus far in case it helps someone else resolve this if it happens to them. Unfortunately, this suggestion hasn't helped me, but I'm still working with Support.

1. On the affected user Teams client, Go to the setting option and choose notification tab
2. Under notification tab, Go to mentions and check if Personal mentions, Channel mentions and Team mentions are set to Banner and Email or not.
3. If they are set to Banner and Email, change it to Banner.
4. And scroll down get to the "Other" Section and in there check for "Missed activity emails".
5. Make sure it is set to "As soon as possible".
6. Once done Save your setting and wait for 5 mins
7. Let the user sign out from teams application
8. Wait for 5 mins and sign back in again.
9. Once you login again, Go to the setting option and choose notification tab
10. Under notification tab, Go to mentions and set  Personal mentions, Channel mentions and Team mentions as Email and Banner.
11. Once done Save your setting and wait for 5 mins
12. Let the user sign out from teams client.
13. Wait for 5 mins and then do the @ mention in one of the channel were affected user is a part of. (Please make sure at this step that user is not logged in teams at any other location and please wait for 5 mins as email always trigger when the user is offline for 5 mins.)

I've also tried other variations of turning the setting for Missed Activity Emails to a couple of the options (i.e. every 10 minutes) with no success. But it is possible that this could help someone else out.