An envelope sealing apparatus for sealing an envelope having a main body and a sealable flap foldable about a hinge between the flap and main body, and sealable thereto. The apparatus comprises a feed path along which an envelope can be fed; a driving means associated with the feed path for feeding an envelope along the feed path; a flap securing means cooperative with the driving means to secure an open envelope flap in contact with the driving means; and a flap sealing means cooperative with the driving means to seal the flap to the main body when the driving means drives the envelope in a flap sealing direction along the feed path. A mail piece creation device incorporating such an envelope sealer is further provided, along with corresponding methods.