Registered fax the document to be sent and the resulting multipage image is encapsulated in an electronic envelope file format that allows time stamp insertion as meta data or as a specific tag.<br> - This envelope document is digitally signed using non reversible cryptography elements and the signature is then printed on the last page of the document for facsimile transmission.<br> - The receipt of the fax acknowledgment and subsequent transmission report validates that the content has been delivered in full to the receiver, including the page containing the signature and informing the receiver about the certified nature of the facsimile transmission.<br>
Fax 2020. There are several indicators of fax capabilities: group, class, data transmission rate, and conformance with ITU-T (formerly CCITT) recommendations. Since the 1968 Carterphone decision, most fax machines have been designed to connect to standard PSTN lines and telephone numbers. Group 1 and 2 faxes are sent in the same manner as a frame of analog television, with each scanned line transmitted as a continuous analog signal. Horizontal resolution depended upon the quality of the scanner, transmission line, and the printer. Analog fax machines are obsolete and no longer manufactured. ITU-T Recommendations T.2 and T.3 were withdrawn as obsolete in