OI Template-IP variable IP is not being included in the email.
By the documentation, you can receive the IP address as a template variable for all alarms:
Why it is not working?
Release : 14.6
Component : APM Agents
The IP template variable supports displaying IP address info ONLY if present. In the case of the OI connector for APM, the current APM agent implementation may not be sending the IP address along with the hostname info to EM for the associated APM vertices and, thus, the IP address may not be present when the OI connector for APM tries to retrieve that information. The OI connector for APM is working as designed and there does not appear much to change in it is implementation for this issue.
User Story US786231 has been submitted to our PM/dev team as an enhancement request in our agent dev backlog for considering always sending ip address info along with host info in the associated vertices.