You can also grant the delegate additional permissions to read, create, or change items in your Microsoft Exchange Server mailbox.
Delegate Access goes beyond just sharing access to your folders.
Similar to having an assistant help you manage your incoming paper mail, you can use Microsoft Outlook to allow another person, known as a delegate, to receive and respond to meeting requests or responses and to send e-mail messages on your behalf.
You can also grant additional permissions that allow your delegate to read, create, or have full control over items in your Exchange mailbox.
Delegates are granted additional permissions, such as creating email messages or responding to meeting requests on your behalf.