This question was originally asked in an internal APM technical forum and answered by Sustaining Engineering.
What dynamic fields are never allowed for SMTP Email Notification Actions?
All supported APM releases.
The list of tokens (potentially producing lists or multiple lines) that are not allowed in an SMTP Email Action Subject field are the following:
See https://docops.ca.com/ca-apm/10-5/en/administrating/configure-webview/create-and-configure-notification-actions - Create and Configure Notification Actions
and https://www.ca.com/us/services-support/ca-support/ca-support-online/knowledge-base-articles.tec1756803.html -- Is it possible to customize the Subject line for Email Notification Alerts that are sent by APM\Introscope ?