When you finally have selected a tool, in most cases they require installation of a piece of software and someone to perform the removal process using the tool or Outlook with add-in. Not all this software is free (some even require payment per duplicate removal of appointments, contacts or e-mail) and some might not even work (MAPI-based tools may not work against Exchange 2013). When continuing your search, you’ll find lots (I mean lots!) of tools and Outlook add-ins, like Vaita’s DIR or MAPILab’s Duplicate Remover. This article describes a manual procedure to remove duplicates entries from your calendar, contacts, inbox or other folders. When looking for a solution, you’ll probably encounter MSKB299349, “How to remove duplicate imported items in Outlook”. Accidental import from – for example – a PST file to a mailbox can lead to duplicate entries. In the past, I’ve seen this happening with Nokia PC Suite and Google Apps Sync for example Entries from the mailbox are treated as new entries and as a consequence are added to the mailbox when synchronizing information back to the mailbox, creating duplicates. Duplicate items can be caused by many things, but most common are: For those involved with Exchange migration projects or managing Exchange environments, at some point you probably have experienced the situation where people ended up with duplicate items in their mailbox.

Delete duplicate emails in office 365