A shared mailbox serves some of the same purposes as a distribution group but in a different manner. A distribution group delivers the same email message to every member of the group. Everyone has their own message with its own properties (read status, importance, reply status, etc). On the other hand, a shared mailbox gives everyone access to a single message with shared message properties. It also provides a calendar, tasks list, contacts, etc that an exchange mailbox has. So, if you just need to broadcast a message to multiple recipients choose a distribution group. If, on the other hand, you need messages to go to a central location where one or more people need to see and act on it then a shared mailbox is recommended.

A shared mailbox works better to group all messages for a function together and more easily allows you to see if someone else has read or responded to a message already. As a result, it does a better job for external people requesting help from an office, not caring who responds just that someone responds. On the other hand, a distribution group does a better job with internal communication between all the people that are members of the distribution group.

A distribution group has the following properties:

• Users in a distribution group receive their own copy of messages sent to the distribution group address
• When replying to an email received through a distribution group, the reply will be sent with the user’s email address. Mail does not typically send from the distribution group address.
• Deleting an email received through a distribution group will delete the email only for the user who deletes the email. Similarly, replying to a message will only be noticeable in the mailbox the reply was generated from.

A shared mailbox has the following properties:

• A shared mailbox is a separate mailbox that users can be given access to. This mailbox has its own Inbox, Drafts, Sent Items, and other mail folders that are not in the user’s primary mailbox.
• Users who are given full access to a shared mailbox will see this mailbox in Outlook underneath their own mailbox on the left hand side of the screen (typically the mailbox needs to be added manually).
• A single copy of any emails sent to the shared mailbox address will be stored within the shared mailboxes email folders and can be read by any user with access.
• Users can also be given send-as permissions which will allow them to change the address in the “From:” field of an email they write. This will send the email from the shared mailbox’s address.
• Deleting an email from a shared mailbox will delete the email for all users who have access to the mailbox.
• The read and replied status of an email message is shared by all users of the shared mailbox.