Office 365 Mailbox Basics

Types of Mailboxes in Office 365

User Mailbox

A user mailbox is a mail destination associated with a particular user. The mailb The mailbox can be accessed via the web client, POP/IMAP, or MAPI (Exchange) via a mail client.

Shared Mailbox

A shared mailbox is a mail destination made accessible to delegated users. The mailbox may be accessed via the POP/IMAP, or MAPI (Exchange) and will automatically be visible from the Outlook desktop client and can be accessed in the web client by using the "Open Another Mailbox" feature.

Mail Flow


Rules can exist at the domain level or be defined within a user or shared mailbox account. Domain level rules are defined in the Exchange administrative console. User level rules are defined from the web client or the Outlook desktop client. Shared mailbox rules are defined in the web client only.


Connectors are route definitions that allow mail to flow into or out of your organization in a hybrid mail environment.