Notification Troubleshoot - Airmail for iOS
Airmail allows you to set separate notification settings for each account. If you are not receiving notifications please make sure to enable the below settings:
Real Time Inbox Monitoring is enabled in Airmail settings > Real time inbox monitoring

And check if the notification is enabled for each of the accounts under Airmail Settings > Tap on the account to enter account settings > Account Notifications (check if it is selected for all)

Try to disable the account for few minutes and then enable it back if above settings are correct
Airmail settings > select account to enter account-specific settings > Enable

Real Time Inbox Monitoring is enabled in Airmail settings > Real time inbox monitoring

And check if the notification is enabled for each of the accounts under Airmail Settings > Tap on the account to enter account settings > Account Notifications (check if it is selected for all)

Try to disable the account for few minutes and then enable it back if above settings are correct
Airmail settings > select account to enter account-specific settings > Enable

Updated on: 09/03/2019
Thank you!