7 ELECTRONIC APPARATUS FOR AUTOMATIC PROCESSING OF MAIL, NAMELY, MACHINES FOR ASSEMBLING, FOLDING, AND INSERTING LETTERS AND DOCUMENTS INTO ENVELOPES, MAIL SORTING AND SEALING MACHINES, MECHANICAL OFFICE MACHINES FOR PROCESSING MAIL, NAMELY, MACHINES FOR ASSEMBLING, FOLDING, INSERTING LETTERS AND DOCUMENTS INTO ENVELOPES; MECHANICAL ENVELOPE SEALING AND SORTING MACHINES; AND MECHANICAL FRANKING MACHINES