Microsoft 365 -Outlook on the Web (How To) Open and Share Resource Calendar Mailboxes

This article documents how-to access a resource calendar mailbox using the Outlook on the Web.

Opening a Resource Calendar Mailbox

Owners (those with full access) of resource calendars can open them in order to share them to users.
Follow these steps to open a resource calendar's mailbox:

  1.  From Outlook on the web, click your profile picture in the upper-right corner and select Open another mailbox...
  2. In the open another mailbox window, type the resource calendar's full UWM email address (i.e., and click Search Directory. If you've opened this mailbox before, the name should appear as you type and you can select the resource mailbox you wish to open from the menu.

  3.  Click Open and the shared mailbox will open in another browser tab.
Note: If you do not have permission (ownership, or full access permissions) to access the resource, you will receive two possible error messages:
  •  A blank screen with the words Bad request.
  •  An error message stating: You don't have permission to perform this action. (This may appear after the first error message if you attempt to open the mailbox again.)

Sharing a Resource Calendar

  1. Once the mailbox for the resource is open, choose Calendar by clicking the Calendar icon in the lower left corner in Outlook on the web: 
  2.  In the left panel, right-click Calendar under the Your calendars heading and choose Sharing Permissions:
  3. The Share this calendar pane will open on the right side of the window. Enter the email address of the user with whom you want to share the resource calendar, select the user when they appear in the search results, and then click the Share button.

Additionally, you can edit the permissions of each user with whom you have shared the resource by again right clicking Calendar and choosing Sharing Permissions.
Here is a description of the different resource calendar permission levels:

Can view when I'm busy

User can see blocks of Busy time on calendar but cannot see any details of the events.

Can view titles and locations

User can see time, subject, and location of items on calendar but cannot see other details such as attendees, notes, or attachments.

Can view all details

User is able to see time, subject, location, attendees, notes, and attachments.

Can edit

User can create, read, edit, and delete all items, regardless of who created them. Events that invite the resource give the option to be accepted by anyone with this permission level. When an attendee is added, a notice that you forwarded the meeting request to additional recipients will be sent to the resource. When editing an event and adding attendees (at least when a room is invited), it will only update if the updates are sent to everyone.


Delegates act on behalf of the resource. If delegate access has been granted, copies of meeting requests will go to the delegate and the delegate can accept or deny the requests for the resource. A notification will be sent to the organizer saying that you have replied on behalf of the resource. This level of access should only be used if someone is completely managing the resource calendar.


Keywordscalendar, resource, resources, OotW, access resource, access, outlook on the web, accessing resource, sharing resource, resource calendar, opening a resource   Doc ID49297
OwnerHelp Desk K.GroupUW-Milwaukee Help Desk
Created2015-03-20 08:08:04Updated2023-09-28 14:53:19
SitesUW-Milwaukee Help Desk
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