These step by step instructions show you how to share your personal and group Outlook mailbox with other people and how they can add the mailbox to Outlook.
I want to add a mailbox that has been shared with me
You'll need to log in with the username and password of the account you want to share.
Right click on the name of the account you want to share and choose Folder Permissions.
In this window you'll need to find the person you want to share the mailbox with.
Once you've done that, choose what sort of permission you want them to have.
Next, go to File, Info, Account Settings and choose Delegate Access.
Please note: You will need to repeat this process for each subfolder you want the person to have access to.
Choose Add, and find the person you want to give access to.
Choose File, Info, Account Settings and Account Settings.
Click on Change in the window that pops up.
Click on More Settings...
Choose the Advanced tab then Add.
Enter the name of the account you've been given delegate permissions to see.
For more information, then visit the Managing another person's account and calendar items on the Microsoft Office pages. This link takes you to an external website.
Find out how to access shared mailboxes in Outlook via Office 365.