Salesforce should automatically determine the recipient of Mail Merge, for detail objects (where the master is a contact record) When I click to create a new mail merge, from a custom object that is a detail of a contact, it leads me to the Task Mail Merge window. where one has to select the contact. I think that salesforce should add the URL parameter to send the contact automatically (since this is a detail of Contact, it's not a problem to determine which one).