Application Engine - Email Distribution - Only PDF Sent

PeopleTools 8.53, Windows, SQL Server

If I generate various file types from an Application Engine, and from the distribution options choose Email (rather than Web or Window), only PDF files are sent in the email (attachment). Other types are ignored.

System Settings for Email seem to indicate this should be sent

Example code in application engine

Local File &file1 = GetFile("file.txt", "W", "UTF-8", %FilePath_Relative);

&file1.WriteLine("file");

&file1.Close();

&file1 = GetFile("file.xml", "W", "UTF-8", %FilePath_Relative);

&file1.WriteLine("file");

&file1.Close();

&file1 = GetFile("file.xlsx", "W", "UTF-8", %FilePath_Relative);

&file1.WriteLine("file");

&file1.Close();

&file1 = GetFile("file.pdf", "W", "UTF-8", %FilePath_Relative);