SharePoint and Exchange Calendar together

(post courtesy Anand Nigam)

One of the cool things in SharePoint 2010 is the ability to show the Exchange Calendar on a SharePoint site, side by side. This is called as Calendar Overlay

This post will walk through how to configure this.

Step 1 (prerequisite)

1. I have a SharePoint Site http://fabrikam which looks like this


2. I also have a calendar “MySharePointCalender” , with a few calendar events entered.


3. I have my Exchange Calendar in Outlook, with a few meeting/events there as well.


4. What we want is to see events from my Exchange calendar show up on the SharePoint calendar.

Step 2 (The actual process)

1. Open the SharePoint calendar  --> Calendar Tools –> Calendar Overlay –>New Calendar,



Fill in the :

  • Name: Give a name to this calendar
  • Type: Select Exchange
  • Outlook Web Access URL: the OWA url of your organization.
  • Exchange Web Service URL: which can be determined as follows:

If your OWA URL is, then the Exchange web Service URL would be

(in other words, from the OWA URL , remove the trailing “owa” and add “ews/exchange.asmx”)


Step 3 (The awaiting Error and the fix)

If you have not previously configured SharePoint to trust your Exchange server, you will receive the following error message:

Could not establish trust relationship for the SSL/TLS secure channel with authority ‘dc’. (GUID)


Here is the fix

1. Get the CA Root Certificate for your domain

(Just a note, there are many ways to get the certificate, I’m taking the one that is less prone to error)

a. Go to the Server where you have the Certificate Authority installed. Open IIS and select the Server Certificates component.


Double click on Server Certificates

Locate the Root Certificate of the CA from the list, here is the one what I have.


(To double check if this it the Root certificate, open the certificate and see the certification path, It should have just one entry (root), that is the name of the Certification Authority, in your domain.). Below the image or my root certificate


b. Now that we have located the certificate, Open it go to Details tab and Click Copy to File

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And now we have the Certificate exported to a file


Copy this certificate to the SharePoint Server, and follow the below steps

a. Open Central administration > Security> Manage Trust


b. Click on New, Provide a Name (I use RootCA), and navigate to the RootCA.cer file you exported in the previous step and Click OK


Now refresh the same calendar and confirm that you can see the Exchange calendar event for the logged in user


Step 4 (Enhance the default behavior)

Although we can now see the Exchange calendar, we can on only see the free/busy status, and not the actual details of the event. It would be good if we could have the details displayed here too. To display details:

1. Open Outlook> File > Options>


2. Go to the Calendar Section > click Free/Busy Options


3. Select any one of the options below, I have selected Full details. Click Apply and Ok and exit out of Outlook.  Now refresh the SharePoint calendar and see the difference.



Additional reading:

Note: The calendar overlay is per user, meaning it will only show calendar items for the currently logged-in user.

Comments (15)
  1. Raf_Nijs says:

    Good informative article! Thanks.


    Raf Nijs

  2. Anand Nigam says:

    Thank you very much Raf, Expect more intresting posts.

  3. apoorva says:

    good article. to the point and above all.. it works !!

  4. cv-team says:

    Good how-to, thanks.

    Unfortunately the screenshots are soo small, even if you click on them..


  5. Peter Malling says:

    Interesting article. Do you know if there is any way to show the calendar of a user on his public my site, to show other users his whereabouts?


  6. Abhishek says:

    Your blog is misleading.

    When creating overlays many would want to overlay the calendar of all team members rather than just "me".

    Your last time of note this is per user basis actually shows that SharePoint as a product is useless for team collaboration.

    Either you people don't understand what team collaboration is OR you are just blogging for sake of blogging (and you do internally know that his stuff is useless).

  7. David says:

    Thanks, this blog post was very helpful. It helped me to resolve the issue for my calendar overlay. Particularly, your explanation of the Exchange Web Service URL was exactly what I needed.

  8. Anonymous says:

    Very useful info. Thanks for sharing.

  9. Anonymous says:

    Thanks for the clarification. Is it possible to display the calendar of a shared mailbox. I see the note specifying that it overlays the calendar of currently logged on user only. But is there any alternate solution to display the calendar of shared mailbox. I tried putting the owa url with the address of shared mailbox but it shows only my personal freebusy info.

  10. Ray Avila says:

    Thanks. Good one!

  11. George says:

    Hi… Excellent, now how about if we want to do the reverse i.e. have Sharepoint calendar items show up in my default Outlook calendar (yes, I know I can pull my Sharepoint calendar into Outlook, but my objective is to get my Sharepoint Calendar items show up in my Calendar/Appointments/Task pane when I’m viewing my mailbox).

    Hope my question makes sense. – Thanks 🙂

  12. Anil Avula says:

    nice information sean,very useful to sharepoint community

  13. Suresh Kumar says:

    Thanks Very useful to me.

  14. Jairam says:

    Very Informative.
    Thank you very much

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