Please follow the steps below:
1. Navigate to Administration | Rules & Notifications | Rules dashboard
2. Search for "Record Severity" and go to the Conditions tab of the rule
3. Update the "Alarm Message" text field with the variable for the text field
4. The variable name is "xxxxxRecordText" (replace xxxx with the severity)
5. Click "Save All" to save the changes
6. Wait for the email alert from the Services and check if this fulfills the requirement
Refer to attached screenshots. Also the length of the record stored may be truncated, so reference the PDF doc attached for adjusting the record storage length.