One of the most frequently used features of Microsoft Dynamics CRM is the Microsoft Outlook plugin that syncs up CRM activities and contact records with your Outlook or Exchange account. I’ve found that after years of use, many clients experience contacts being duplicated, appearing two or more times in Outlook. This is certainly frustrating for users! After seeing this a few times at different clients, I did some investigation on why this occurs and how to prevent it. It’s actually a very common occurrence that will be problematic for most organizations.


When contacts are synchronized from Microsoft Dynamics CRM to your Outlook, the Outlook plugin creates matching contact records in your Outlook account. Problems start to occur if you re-install Outlook, or migrate to an Outlook installation on a new workstation. For most, that means every 2-5 years you’re exposing yourself to a potential duplicate headache! 

Here’s where the duplicate contact records come from:

  1. When the CRM for Outlook plugin synchronizes for the first time, it creates synced CRM contacts in Outlook
  2. Outlook is installed on a new workstation or is uninstalled and re-installed on the same workstation 
  3. The new installation of Outlook sees the contact records, but does not know anything about the synchronization, so they turn into normal Outlook contact records
  4. When the CRM for Outlook plugin synchronizes for the first time on the new installation, it creates new synced CRM contacts in Outlook. 
  5. CRM’s Duplicate Detection Rules only apply when synchronizing from Outlook to CRM and not from CRM to Outlook, so it assumes all the contacts are new
  6. Now, Outlook has duplicate contact records for all originally synced CRM contacts: An Outlook copy and a CRM synced copy

Left unchecked over the course of several years, you may end up with two, three or more copies of the same contact record! How many times have you upgraded workstations or wiped and re-installed since you’ve been synchronizing with CRM?


In order to avoid creating duplicate contacts, a little advance planning is necessary. Before you upgrade workstations or uninstall Outlook, follow these steps in your original Outlook client:

  1. Open the Personal Options settings screen for the CRM plugin
  2. On the Synchronization tab, click Outlook Filters 
  3. Select all the filters, and click Deactivate
  4. Synchronize with CRM, and all synchronized Outlook records will disappear
  5. Set up your new Outlook installation, install the CRM plugin
  6. Follow steps 1-4 again, but confirm the filters are Activated
  7. Now, Outlook is synchronized with CRM with all your expected records, and there will not be duplicates

Give it a try, and avoid the headache of duplicate contact records the next time you re-install or move workstations!

Like this post? Share it!