5 Reasons Why Outlook Gets Duplicates

TIP: Latest version of Deduper for Outlook allows to remove duplicate emails automatically with a single click.

There are many reasons why Outlook can get duplicates. However, below you can find the 5 most common, and solutions for each one.

  1. Leave a copy of the messages on the server is checked. Solution – uncheck it on Account Settings > More Settings > Advanced.
  2. Email rules that create duplicates. Solution – review your rules; disable all of them to check if it is indeed the cause of the problem first.
  3. Failed import. Solution – delete the emails manually, or by using outlook duplicate removal software such as Deduper for Outlook.
  4. Email forwarding from one account to another. Solution – review rules that forward the email.
  5. Two Outlook instances running. Solution – close Outlook restart your PC and make sure when you open your Outlook again, that you do this only once.

In every case, it should only prevent future duplicates. However, this does not remove existing duplicates. We recommend using outlook duplicate removal software such as Deduper for Outlook to do this.