How can I dial without a dialtone (for example, from behind a PBX)?
Choose Page Sender Setup from the Send via popup. This will launch Page Sender Fax Center and take you directly to the fax preferences. Click Modem in the toolbar. Add X3 at the end of the Modem Initialization: -iZ -i&FE&D2S7=120 -i&C0X3. If you would also like your fax modem to ignore busy signals (sometimes the PBX or voicemail dialtone sounds like busy to the modem), use X1 in place of X3.