1944 German Dienstmarke 8 Rpf single, Tallinn/Reval local (damaged)

Local official letter, Reval/Tallinn, 30.6.1944. Franked with an 8 rpn official postage stamp specially designed for German authorities (Dienstmarke). Scarce franking, local rate only introduced on July 1, 1943. In the lower left corner of the envelope is the sender’s cachet (Briefstempel) required for use of official mail. German rate 8 rpn, local letter up to 20 g (1.7.1943-1944).
Note the cover is damaged from back, roughly opened, about 2/3 if back side is missing. With original letter content.