[Mail] Fetch new data not working as expected on manual mode

Device: iPhone 6 64GB

iOS Version: 10.2.1

How to reproduce:

1. Configure 2 different email account: 1 IMAP and 1 Exchange (office365 for me).
2. Go into Settings->Mail->Fetch new data and disable push
3. Set "Fetch" for the IMAP account
4. Set "Manual" for the Exchange account
5. Choose "Fetch every 30 mins" on the bottom
6. Background app refresh is set to "Off"

Now use the iPhone without opening the Mail APP and from another different device/PC/MAC send 1 or more email to the Exchange account.

Expected result: until I open the Mail APP on the iPhone, I will never receive notification/badge for new email on the Exchange account

Actual result: after more or less 2-3 hours you will receive the notification of new incoming emails for the Exchange account on the Mail APP badge and on the notification center.

This was working as expected on iOS Rel 9, the issue started from iOS 10.

Thanks.

King Regards, P.