PURPOSE: To obtain a simple and convenient mailer assembly composed of an intermediate ply and a front and back ply for continuous recording.

CONSTITUTION: On the mailer assembly, the information printed on the cover 74 can be continued to the intermediate ply 52 and the back ply 38. The cover 74 is crimped to the front ply 36 and the back ply 38 by paper staple 75 or like. A letter from a sender is written on the cover 74. The tab 48 is separated from the back ply 38 by holding down the tab 48 along the cutting lines 28, 29 to peel off the adhered line 44 besides the right edge 20. The intermediate ply 52 is pulled out from the mailer assembly by holding the right side of it out along the cutting line 66 besides the adhered line 64, left side of the mail. The intermediate ply 52 is stored with the receiver for filing. The body 50 of the front ply 38 and the body 80 of the back ply 38 form an envelope for reply mail. A check and others are enveloped in it and the right or side part 82 of the back ply 38 is folded along the line 70 and moistening the adhesive part 72 seals the envelope.