Symptoms
Assume that you use email subscriptions in Microsoft SQL Server 2016 Reporting Services (SSRS). When you upgrade from SQL Server 2012 Reporting Services to SQL Server 2016 Reporting Services, you notice that the subscriptions fail with an error message that resembles the following:
An invalid character was found in the mail header: ','
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
Resolution
This issue is fixed in the following cumulative update for SQL Server:
About cumulative updates for SQL Server:
Each new cumulative update for SQL Server contains all the hotfixes and all the security fixes that were included with the previous cumulative update. Check out the latest cumulative updates for SQL Server:
References
Learn about the terminology that Microsoft uses to describe software updates.