Postage accounting system including means for transmitting a bit-mapped image of variable information for driving an externel printer

A postage accounting system comprising: structure means (12) for accounting for postage; printing structure (13) externally of the accounting structure, the printing structure including a printing module (14) and a computer (15) for controlling the printing module, the printing module including printing apparatus and structure for sequentially feeding each item of a predetermined plurality thereof to the printing apparatus for printing thereon, the computer programmed for sequentially transmitting variable information for each item to the accounting structure (12), the variable information including at least a portion of the mailing address for each item; the postage accounting structure (12) including structure (86) for connecting the accounting module in communication with the printing structure (13), the accounting structure (12) including structure for sequentially encrypting the variable information received for each item, the accounting structure (12) including a microprocessor (18), the microprocessor programmed for transmitting a bit-mapped image of fixed information to the printing structure (13) for printing on each item, and the microprocessor (18) programmed for separately sequentially transmitting a bit-mapped image of the encrypted information for each item to the printing structure for printing thereon.