After attaching a file to a message being composed, the attachment has a file name and the size is displayed in brackets. To ease reading, the size should be either divided by thousands (the separator should be user defined in preferences so as the format for dates) or displayed in using the prefixed units (kb, Mb). The units should not be omitted in any case.
When displaying a received or sent message, the attachment sizes are not displayed. May be they should?