Email Troubleshooting - Duplicate Emails

  • Applies to: Grid
    • Difficulty: Easy
    • Time Needed: 10
    • Tools Required: AccountCenter access
  • Applies to: All DV
    • Difficulty: Easy
    • Time Needed: 10
    • Tools Required: Plesk administrator access
  • Applies to: All DV
    • Difficulty: Easy
    • Time Needed: 10
    • Tools Required: Plesk administrator access


If you receive multiple copies of the same email, there may be a connection problem somewhere in your email delivery or downloading process. Read through these specific scenarios for further assistance.


Every once in a while, I get two copies of an email.

Likely cause: This may be due to a failure of confirmation that the email was already delivered, somewhere in the email delivery process. This may be at any point between the first sending from your computer, or the final delivery on the server.

Solution: Sometimes antivirus software on your computer or local network can trigger your email software to behave as if it has not sent a message, when it already has. This is especially true of Outlook. You may need to look into this further if it becomes a common issue. If the problem is occurring outside of your local network, unfortunately, it may be impossible to determine where the duplication occurred.

How email servers deliver email:

This example will reference a message sent from to

  1. After both servers negotiate a connection, the mail server for pushes the message to the receiving mail server.
  2. The connection between the two servers remains open while scans the message for spam content and viruses.
  3. Once the message has been declared safe for delivery, queues it for local delivery to Sue's mailbox.
  4. When the message reaches Sue's mailbox on, a message is sent back to informing it of a successful delivery.

This process ensures that all email is properly scanned, delivered, and accounted for. However, in very rare cases, an interruption between steps 3 and 4 can cause a message to be delivered more than once.

For example, if the connection is interrupted after queues the message for delivery to Sue's mailbox, but before a confirmation can be sent back to, the sending server will try to redeliver the message.

Since the original copy was queued for local delivery it will come through, but since the sending server never received confirmation, it will try to deliver again - resulting in duplicate emails. This is more likely to happen when the server is under intense load, or when the message is coming over a high-latency network. The issues leading to the interrupted connection can originate with either the sending server or the receiving server.

This is a temporary problem, and normally only a few copies of the email will be delivered. They can safely be deleted.

I get multiple copies of every email.

Likely cause: You have multiple forwarders set up. Let's say person A is getting the double copies. Perhaps emails to B forward to A and C, while emails to C also forward to A. So A is getting the emails from both B and C.

Solution: Check for forwarders both with (mt) Media Temple and in any third-party email addresses that you use.

I get never-ending copies of one email.

Likely cause: The sender's computer never realized it sent the email. This can occur particularly with Outlook and some antivirus software.

Solution: Ask the sender to remove the email from their Sent folder and their queue, and/or to temporarily disable their antivirus to see if that resolves the issue.

My entire inbox is downloading again.

Likely cause: You are using a POP connection to the server, and the connection to the server has been reset (the reset can occur anywhere between you and the server, and is most often due to regular maintenance on the email server that includes some type of system reboot). The emails were left on the server rather than being downloaded.


  1. To stop an in-progress download, take that email account offline, or quit your email application.
  2. Next, you will need to clear out older emails from the server so they don't download again when you reconnect. You can do this through webmail. Access your webmail at
  3. To keep this from happening in the future, you may be able to either configure your email software to delete messages from the server after a certain period of time (usually an advanced setting), or you may want to switch to using IMAP instead of POP. IMAP always stays in sync with the server, so there's no danger of re-downloading messages.

See also