HP Officejet 350 All-in-One Printer - Manual (Page 135)

Method 1:`Adding documents to a fax sent from a
Windows application
1. First, follow the steps listed in "Sending a Fax from a Windows
Application." Click the Append Pages button in the Special box of the
Send Fax dialog box. (If you include a cover page, it will not show
the total number of pages in the fax.)
2. When you click the Send Fax button, the fax is displayed with the
Collect dialog box.
3. Complete the procedure by following the steps listed in "Using the
Collect Dialog Box" below.
The Append Pages button