An apparatus and method for sheet folding and sealing to produce mailable letter-like objects, each from a single preprinted sheet, comprises a feed mechanism for the feed of sheets in seriatim while continuous beads of adhesive are applied to each sheet along lateral portions thereof. The sheets are fed into a buckle folder which makes one or more transverse folds in each sheet while transversely-spaced spots of adhesive are applied along a transverse line across the sheet. The buckle folder is structured so that it has fold pans on one side; and, both the input and output are on the other side. The folder also includes folding and sealing rolls that seal folded-over sheet portions to close and seal the sheet into a letter-like object. A perforator perforates the object so that tearing along the perforations facilitates opening.