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 to the e-mail to fax service that still uses fax modems at least one way. Computer modems are often designated by a particular fax class, which indicates how much processing is offloaded from the computer's CPU to the fax modem. Several different telephone line modulation techniques are used by fax machines. They are negotiated during the fax-modem handshake, and the fax devices will use the highest data rate that both fax devices support, usually a minimum of 14.4 kbit/s for Group 3 fax. Note that "Super Group 3" faxes use V.34bis modulation that allows a data rate of up to