When we choose in the action information "Include Request Email" for the request email type, the email notification fails. Otherwise the email is delivered.
Release :17.3
The root cause of the notification failing is because of a missing image file from the Service catalog installed directory.
You will notice the following error in the logs:
C:\Program Files\CA\Service Catalog\filestore\themes\
1) Please make sure that the header_logo.png file is present at C:\Program Files\CA\Service Catalog\filestore\themes\common\images\logo folder.
2) In case you are replacing the logo with a custom logo, change the name to header_logo.png.
3) Check if the image file is corrupted, replaces if found from another working environment.