Mail directives are used to notify users of updates using the standard notification layouts. They can either complement the existing inbuilt notification rules or replace the inbuilt rules, depending on the value of the behavior setting named SUPPRESS_STANDARD_EMAIL_LIST. The mail directive will always contain rules that generate the notification based on the notification layout for the issue being inserted or updated.
Note there is a key difference between the mail directive and the mail action rule which is typically used within the preupdate directive. The mail action is used to send an email based upon a template specified within the action.
