Abstract: Methods, computer programs, and apparatus for performing format conversion of a file attached to an electronic message. A message entered by a user is accepted. The user's selection of a file is also accepted, and the file is copied for accompanying the message as a file attachment. The file attachment is in a first file format of a file category. The file attachment is converted from the first file format to a second file format of the file category. The message entered by the user is transmitted, and the transmitted message is accompanied by the converted file attachment in the second file format of the file category.