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In Outlook on the web (OWA), right-click the Folders item in the left navigation panel and then choose/click on Add shared folder.
Enter either the shared mailbox name or username click Add. In this example the name is Shared Account and the username is sharedmb@uwaterloo.ca
As you complete this field, a list of suggested account names will display.
Once entered, the account name will appear in the list of mail folders/boxes:
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