In Exchange Online , which is a part of Microsoft Cloud Service Office 365 , you can grant access to any folder which is part of your mailbox to any colleague of yours. This takes collaboration between Team members to the next level. Delegate access enables users to access some or all of the mailbox owner's folders and act on behalf of the mailbox owner. The mailbox owner can be a user, or a resource, like a conference room.
To know more about Delegate Access, please click on the link below :
with warm regards
Microsoft MVP 2009
Microsoft Worldwide Partner of the Year 2011 & 2007