the positioning assembly is used in a thermal printing postage meter having a base supporting a registration wall and a deck , and a thermal print head fixably mounted to the registration wall above a portion of the deck to define a print station for printing a postage indicia on an envelope having a leading edge positioned on the deck in the print station . the positioning assembly includes a stop lever and a position support arrangement . the position support arrangement provides support for the stop lever such that in a first or home position , the stop lever obstructs the longitudinal positioning on the deck beyond the proper print station location . the obstruction is caused by encounter of the stop lever with the leading edge of the envelope . during initiation of the print cycle , the stop lever is repositioned to a second position removing the stop lever from obstructing the leading edge of the envelope .