You can set the time that elapses before sending operations terminate (automatically) if you do not receive a notification e-mail message (MDN) from the recipient when you send an I-fax in the Full Mode.
1.
Press 
→ [Function Settings] → [Send] →[E-Mail/I-Fax Settings] →[Full Mode TX Timeout].
→ [Function Settings] → [Send] →[E-Mail/I-Fax Settings] →[Full Mode TX Timeout].2.
Press [-] or [+] to specify the full mode RX timeout time → press [OK].