Outlook 2003 – POP3 – Downloading duplicate mails

Today I got a mail from one of the clients saying his outlook is downloading same messaged again and again for the past couple of days and the mails are there even after deleting them number of times. I took remote of his computer and there were thousands of mails accumulated over the past couple of days.

This can happen due to a number of reasons including but not limited to:

  • Multiple mail forwards set
  • Multiple email accounts setup
  • Leaving a copy of mail on the server
  • Corrupt outlook installation
  • Connection issue (Internet and application)
  • Antivirus

In this case, the customer had around 63 mails to be downloaded, a slow internet connection and Kaspersky installed. When outlook was trying to download mails, the antivirus was kicking in and scanning the emails in the meantime the connection with pop server was getting timed out. Since, the connection was not getting properly closed, all those emails were again getting downloaded next time outlook was trying to sync.

To fix the issue, I turned off the antivirus and set outlook to download only headers, hit F9 and it worked like a charm. Once it had all the 63 mails downloaded, I scanned them manually with Kaspersky and then changed the outlook download setting to download full items. Monitored it for 4 hours and everything seemed okay.