If you receive an email notice that you have been granted access to share another person's task list, you can accept or decline the share.
When you accept the share, the shared task list displays in your Tasks list in the Overview pane.
Click Accept Share in the email. The Accept Share dialog opens and describes the role granted to you.
Before you accept, you can customize the task list name and select a color to display the list in your Navigation pane.
(Optional) Select to send a confirmation back to the Grantor.
Click Yes. The shared task list is added to your task list on the Navigation pane. The message is moved to your Trash folder.