Why do I receive duplicate copies of email messages?

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There are three reasons why you might receive multiple copies of incoming email messages. This page describes the reasons; please contact us if this page doesn't explain why it's happening to you.

Multiple accounts in your mail program

If it happens with all mail, and you use an email program like Outlook, Eudora, Thunderbird or Mac OS X Mail on your own computer, you may have accidentally configured that program to have two separate accounts checking the same mailbox.

One way this can happen is if you have two domain names with us, and one of them is a domain name alias for the other. If you set up two accounts in your mail program to read mail sent to each domain name separately, you’ll see duplicate mail because there’s really only one mailbox on our servers. The point of a domain name alias is to make the two domain names interchangeable, so adding two mail program accounts to connect to the same mailbox using two versions of the address is the same thing as connecting to the same mailbox twice. If you have a domain name alias, you should just set up a single account in your mail program to read your “preferred” domain name — the one you want other people to see when you send mail.

One address forwarding to multiple mailboxes

A second possibility if it happens with all mail is that you've set up a single forwarding address on our servers to forward to two different mailboxes.

For example, if you set up sales@example.com to forward to both president@example.com and ceo@example.com, and you read both the "president" and "ceo" mailboxes, you'll see two copies, even though the sender only sent one copy.

The sender is sending to multiple addresses that deliver to the same mailbox

If it only happens with mail from one sender (or from a small number of senders), a third possibility is more likely.

If you've set up two forwarding addresses (or a catch-all forwarding address) to deliver mail to the same mailbox, and the original sender addressed the message to those two different addresses, you'll get two copies.

For example, if you set up both president@example.com and ceo@example.com to forward mail to the_boss@example.com, and someone sends a single message that's "To: president@example.com, CC: ceo@example.com", you'll get two copies.