Computer method, apparatus and system reduces size of attachments for an electronic communication. The method/system automatically selects a part (portion) of a working document to serve as the electronic communication attachment or upload. A monitoring unit monitors sender-user activity with respect to the working document and logs indications of the portions of the working document that are read by the user. During email composition, an attachment engine automatically selects the logged and indicated document portions to serve as an attachment reduced in size. During other electronic communication composition, such as to a blog, wiki or computer network forum, the attachment engine automatically selects the logged and indicated document portions to serve as the upload reduced in size.