Shared mailboxes make it easy for a specific group of people to monitor and send email from a common account, like public email addresses (for example, email@example.com or firstname.lastname@example.org). When a person in the group replies to a message sent to the shared mailbox, the email appears to be from the shared mailbox, not from the individual user.
Shared mailboxes are a great way to handle customer email queries because several people in your organization can share the responsibility of monitoring the mailbox and responding to queries. Your customer queries get quicker answers and related emails are stored in one mailbox. The mailbox delivers to users’ OWA and Outlook desktop clients. However, shared email accounts do not forward to mobile devices. The reason is that shared accounts are aimed at departmental use so that the first available person with office resources can deal with incoming mail.
A shared mailbox does not have its own user name and password. You cannot log into a shared mailbox directly using Outlook or Outlook Web App. You must first be granted permissions to the shared mailbox, and then you access it using Outlook or Outlook Web App. You don’t need to assign licenses to shared mailboxes, except when they are over their storage quota of 10 gigabytes (GB). If your shared mailbox goes over its quota of 10GB and you don’t assign it a license, after one month the shared mailbox will be locked. You can avoid having to assign the license by using archiving to avoid going over your quota.