Under Email Integration--> problem notification you can see the format of mail even you can edit what you want to send but the default message should be there.
something like this:
Subject
Available placeholders
{ImpactedEntity}: Entity impacted by the problem (or x impacted entities when there are multiple).
{PID}: Unique system identifier of the reported problem.
{ProblemID}: Display number of the reported problem.
{ProblemImpact}: Impact level of the problem. Possible values are APPLICATION, SERVICE, or INFRASTRUCTURE.
{ProblemSeverity}: Severity level of the problem. Possible values are AVAILABILITY, ERROR, PERFORMANCE, RESOURCE_CONTENTION, or CUSTOM_ALERT.
{ProblemTitle}: Short description of the problem.
{ProblemURL}: URL of the problem within Dynatrace.
{State}: Problem state. Possible values are OPEN or RESOLVED or in some cases MERGED when the problem has been merged into another problem.
{Tags}: Comma separated list of tags that are defined for all impacted entities.
