Speaking on behalf of the overburdened World Wide Web, Internet representatives announced Monday that all Sunday e-mail service would be discontinued as part of a new cost-cutting measure. 'Any correspondence sent after 11:59 p.m. on Saturday will now be delivered by noon on Monday,' Internet spokeswoman Sharon Jervis said. 'Users should expect further delays during national holidays or on days affected by adverse weather conditions.' Jervis added that, starting Mar. 30, all e-mail attachments will also be charged by weight. 