This change is consistent with Microsoft's cloud push. Administrators are able to work with the same interface whether they are running Exchange on-premises, online, or a hybrid setup. At the browser open the EAC from:
https://<Client Access Server>/ECP

Today we won't get into lengthy EAC discussions. Instead I have tons of screen grabs. As we shall see, although the EAC looks different anyone who worked with Exchange 2007/2010 will find the new interface very intuitive. So this visual tour is a good starting point for those having some experience with Exchange.

Recipients Category

The interface is organized into 11 categories accessible from the left navigation pane. This includes Recipients, Permissions, Compliance Management, Organization, Protection, Mail Flow, Mobile, Public Folders, Unified Messaging, Servers and Hybrid. Here is the top most Recipients category:

For each category we get a set of tabs at the top, breaking down further the category settings. In this case we have Mailboxes, Groups, Resources, Contacts, Shared and Migration.

Creating a new mailbox will of course be one of the first things to do. So we just click the add button for Recipients | Mailboxes.

Creating a mailbox for the first time is likely to return: 'Error: Load balancing failed to find a valid mailbox database'. To avoid that, click 'more options' and set the Mailbox Database field with the database created at installation time. With that set, we complete creating our first mailbox.

Getting back to the main view and selecting a mailbox, the 'Details pane' exposes the item information. This pane also allows us to directly edit the selected item by clicking the various links it exposes.

Here is a dump of what the Details pane is showing in this case:

Administrator
User mailbox

Administrator@wtest-dom1.local
Title:
Office:
Work phone:

Master account:
Phone and Voice Features
Unified Messaging: Disabled

Enable| Edit details
Enable
Mobile Devices

Disable Exchange ActiveSync

Disable Exchange ActiveSync

Disable Outlook App for Exchange

Disable Outlook App for Exchange

View Details
Compliance
Archiving: Disabled

EnableEnable
Disable| Edit details
In-Place Hold
User is not under hold
Show Details
Email Connectivity
Outlook Web App: Enabled

Disable| Edit details
Disable
Move Mailbox

To Exchange Online
To another database

A very welcome addition is the Recipients | Shared (mailbox) category. Here we finally have a simple interface to create mailboxes that are to be accessed by multiple users. Moving to the Shared tab and clicking add we see how easy it is to assign users permissions over the mailbox.

We can allow Full Access or Send As permissions simply by adding users to the correct list:

Full Access - Allows the delegate to log into this shared mailbox as a mailbox owner and the delegate has access to everything the mailbox owner has access to.

Send As - Allows the delegate to send email from this shared mailbox. From recipient's perspective, the email is sent by this shared mailbox.

The EAC also provides an interface for migrating mailboxes. So I select Recipients | Migration and hit add to see what the 'new local mailbox move' wizard looks like: