Brother MFC 8840D - Manual (Page 105)

10 - 16 FRONT PANEL SETUP MENU
Notification
Notification feature when switched to On sends two fields of data in
addition to the image data which requests a notification from the
receiving station for successful reception. The receiving I-Fax station
must support the
MDN standard in order to be able to understand the
request and consequently submit a notification message confirming
successful receipt of the I-Fax.
1 Press Menu , 6 , 4 , 3 .
2 Press or to select On or Off .
3 Press Set .
4 Press Stop/Exit .