Brother MFC-3420C - Manual (Page 116)

6 - 4 USING BROTHER PC-FAX SOFTWARE
Outside line access
If you need to enter a number to access an outside line, enter it here.
This is sometimes required by a local PBX telephone system (for
example, if you must dial 9, to get an outside line in your office).
Include header
To add header information to the top of the fax pages you send,
check the Include header box.
Address Book file
To select you must enter the path and file name of the database file
which contains the address book information.
—OR—
Use the Browse button to find the database to select.