Between 06/01/2018 17:00 UTC and 06/05/2018 08:00 UTC, all customers may have experienced delay in Alert/Information emails in East US region. The impact was due to an issue in one of our dependent services which is responsible for sending emails. Our Devops team has identified the issue and deployed the fix to address this. The issue is now mitigated and these emails might have triggered in between 06/05/2018 08:00 UTC and 06/05/2018 18.30 UTC.
We apologize for any inconvenience.
-Sindhu