The disclosed and claimed concept describes a handheld electronic device that has the capability to process electronic messages that originate from an electronic mail service using the features that are supported by the electronic mail service. The hollow-fiber membrane possess on its inner surface a separating layer and an adjoining open-pored supporting layer, and has an ultrafiltration rate in albumin solution of 5 to \u226625 ml. A charging connector is associated with each tablet receiving area and is constructed and arranged to be connected with an associated tablet for charging at least one battery of the associated tablet. The blowout unit and the exhaust unit are arranged one over the other in the transporting space to separate the transporting space of each cell from that of another cell. At the end stage of compression molding, a rim of molding material extending sideways is molded to the upper part of the side walls when the mold is kept closed in such a way that a mold cavity corresponding to the rim is formed by moving a counter surface inside the mold backwards from a surface opposite to it, after which the molding material is introduced into the mold cavity.