Brother MFC-3420C - Manual (Page 103)

USING THE WINDOWS ® XP-BASED BROTHER SMARTUI CONTROL CENTER 4 - 27
PC Fax setting (PC-FAX using the
Brother Fax Driver)
The machine includes a PC-Fax driver, which allows any Windows
®
Application to send a Fax as simply as printing an original . The
Brother SmartUI automatically configures the Fax button to use the
Brother PC-FAX driver no user configuration is required.
The Scan Action tab is set to Application and should not be changed.
To change the PC-FAX settings click the Link Preferences button,
found in the Configuration tab.