An email address may be associated with more than one inbox on more than one server. An email sent to such an address may not be delivered automatically to all the inboxes because mail transfer agents follow a rule that each email address is uniquely associated with one inbox on one server, so such agents stop after delivering email to the first inbox. A switching mail transfer agent processes email to deliver to more than one inboxes associated with the address substantially synchronously and substantially without duplicates being delivered to the same inbox.