If you would like to give a person permission to access a folder in your Office 365 account it involves giving permission in two places. First, you need to give the person permission to access your Office 365 e-mail account Mailbox (e.g., Mailbox - Doe, Jane) then you need to give the person permission to access each Folder/Subfolder you want to share. The process for sharing your Mailbox and your Individual folders is the same. 

Sharing your folders using Outlook

1. Right-click on your Mailbox name (e.g., joebloggs@centuragroup.co.uk) and select Folder Permissions.
2. Select the Add button.
3. Select the person you wish to give permission to from the address list and press the Add button.
4. Press the OK button. 
5. Click on the person's name and select the appropriate permissions from 'Permission Level. Reviewer rights are recommended at the Mailbox level.  The option "Folder Visible" must be selected. 
6. Click the OK button.

Now you will need to give permissions to the actual mail folder.

1. Right click on the folder you wish to share
2. Select Properties or Sharing Permissions (depending on your Outlook version) and click Permissions tab. 
3. Click the Add button. 
4. Select the person you wish to give permission to from the address list and press the Add button.
5. Press the OK button.
6. Click on the person's name and select the appropriate permissions from 'Permission Level:' drop down list (e.g., Owner, Contributor...).  
7. Click the OK button.
8. To share additional folders/subfolders, right-click on the folder or subfolder you wish to share and follow steps 2-7 above.

Accessing another person's folder(s) using Outlook

To open another persons folder(s), you need to make sure that you have been given permission to their Mailbox account and the Folders/Subfolders in that Mailbox account that you wish to access (e.g., See steps 1-7 above). Then proceed with Step 1 below.

1. Choose File | Account Settings.
2. Select your Office 365 account and click the Change button.
3. Click the More Settings button.
4. Click the Advanced button.
5. Under Mailboxes, 'Open these additional mailboxes:' click on the Add button and type the person's name in the window (e.g., Jane Doe), and click the OK button.
6. Click the OK button.
7. Ciick the Next buton.
8. Click the Finish button.
9. Restart Outlook.

The folder will appear at the bottom of your folder list.

Sharing your folders using OWA

1. Login to OWA
2. Choose Mail to open your Mail folders.
3. Right click on your name in the Mailbox list
4. Select Permissions
5. Click the + button to add a new person
6. Type the name of the person you are sharing the folder with and click Add
7. Select the desired permission level (Reviewer is recommended) - Folder visible must be a selected option.
8. Click OK

Now you will need to give permissions to the actual mail folder.

1. Right click the folder you wish to share and select Permissions.
2. Click the + icon and type the name of the person you are sharing the folder with and click Add
3. Select the desired permission level 
4. Click OK
5. Repeat steps 2-7 for the folder(s) you wish to share.

Accessing another person's folder(s) using OWA

1. Login to  OWA
2. Click Mail to open your mail folders.
3. Right click on your name in the folder list.
4. Choose Add Shared Folder
5. Type the name of the person whose folder you wish to open and click Add
6. The folder will appear at the bottom of your folder list.