Collection letter messages can be written and saved under Customer/Maintenance/Document messages.
This message text can then be used for each collection letter that is sent to a customer. Click on the ‚Add‘ button in the toolbar/ribbon to add a new document message, as shown in the screenshot below.
(Click on screenshot to enlarge.)
Select ‚Collection‘ or ‚Collection Letter 1, 2 or 3‘ to write a collection letter document message.
Read more about document messages here.