Although SharePoint Server is designed to provide a collaborative user environment, it isn't the only application that enables teamwork. A user might, for example, use a SharePoint team site to store documents related to a particular project, but turn to a mail client such as Outlook to communicate with team members.
The problem is this scenario requires a user to switch back and forth between collaborative applications. As has been noted in other contexts, this kind of toggling between applications can undercut the immediacy of collaboration and hinder its benefits. A SharePoint-Exchange integration can help in scenarios like these.
Currently, no application exposes all the collaborative features from various Microsoft Server products. When properly configured, however, Microsoft Outlook can be a client for Exchange Server and SharePoint.
Most workers use Outlook as a client for accessing their Exchange Inbox, calendar and other tools. The application has also long had the ability to open multiple mailboxes. When the capability was first introduced, it was largely viewed as a mechanism to enable administrative assistants to access their bosses' email accounts. But site mailboxes, which were first introduced in Exchange Server 2013, have made Outlook's ability to open multiple mailboxes much more useful.
A site mailbox is simply an Exchange Server mailbox that is intended to be shared by multiple users. As the name implies, site mailboxes are tied to SharePoint team sites -- they're useful because a message can be sent to team members via the one mailbox. While a distribution group can serve a similar purpose, there is a key difference between site mailboxes and distribution groups: Distribution groups represent a collection of mailboxes. When you send a message to a distribution group, each group member receives a copy. Conversely, site mailboxes are shared -- anything sent to, or placed into, a site mailbox is accessible to all team members. As such, site mailboxes can ensure that all messages related to a particular project remain centralized.
As previously mentioned, Outlook can open multiple mailboxes. A user can configure Outlook to open his own Exchange mailbox and other site mailboxes. If a user wants to share a message with his team members, he could send an email message to the site mailbox. Or he could drag a message from a private mailbox to a site mailbox to make the message available to anyone with access to the site mailbox.
Although site mailboxes are designed to be shared among team members, a site mailbox isn't just a shared user mailbox. Like a user mailbox, site mailboxes contain folders such as Inbox, Deleted Items, and Junk Email, but they also contain a Documents Container, which is connected to a SharePoint document library. This means users can drag an attachment from an email message into the Documents Container, and the message attachment will be automatically added to the corresponding SharePoint document library.
Most SharePoint team sites also contain a calendar. Microsoft makes it possible to access a SharePoint team site's calendar from within Outlook. To do so, a user needs only to open the SharePoint team site, access the site calendar and click the Connect to Outlook button found on the toolbar. By doing so, a user can make the calendar accessible through Outlook -- it's found on the Calendar tab in the Other Calendars section. This means users can use Outlook to create and view appointments on the team site calendar without ever having to open the team site. In fact, a user can even configure Outlook to display a SharePoint calendar and the user's own calendar side by side through a single interface.
While Outlook is not designed to be a "SharePoint client," document libraries and team site calendars can be exposed through Outlook to create greater SharePoint-Exchange integration. Microsoft also makes it possible to create a shared site mailbox for SharePoint team sites, and these site mailboxes can also be exposed through Outlook.
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