This issue is due to recommended workarounds for two issues:
The Reply/Reply All button not appearing. The solution was to set the glide.ui16.emailStreamResponseActions system property to true to return the buttons to the email entry in the activity stream.
The frame disappearing as soon as the window was clicked into, resulting in an empty email record created with no value in the instance column. The solution involved creating a UI macro.
Although these workarounds were effective, the URL produced looks like the following example:
The omission of sysparm_sys_id appears to cause the instance value in the resultant sys_email record to be missing. This seems to cause the email not to be captured in the record history of the source incident or RITM.
Steps to Reproduce
Create the glide.ui16.emailStreamResponseActions system property with type true|false and set to true.
Import the attached UI macro.
Expand the activity stream entry for email in the incident.
You might have to send an email to create one.
Note that rather than sysparm_sys_id being set to the sys_id of the source record, it is empty.
Import the attached UI Macro (workaround-PRB1262450.xml) to resolve the issue.
Related Problem: PRB1262450