Quick messages are not applied to email client if the Body field type on the quick message table (sys_email_canned_message) is String.
Steps to Reproduce
On the Quick Message table (sys_email_canned_message), modify the dictionary record for the field Body to be the type String.
For more information, see the product documentation topic Quick messages.
Create a new quick message with some text in the body.
Navigate to an incident and open the Email client.
Apply the newly created quick message.
Note that the quick message selected is not being applied to the Email client body.
On the Quick Message table (sys_email_canned_message), set the body field type as HTML rather than String.
Related Problem: PRB1244841