When mail needs to be internally distributed from a single email address to multiple users, one method of distribution is a shared mailbox. Shared mailboxes allow for mail to be managed, read and replied to by multiple users whilst maintaining changes for all members.
A shared mailbox differs from a distribution list, which also allows multiple users to see mail from a single address as a distribution list will send mail to all of it’s members as a standard forward, which can result in multiple users responding to or actioning an email.
You can configure a shared mailbox through the Office 365 Admin portal at https://portal.office.com/adminportal/home this will require a ‘Global Administrator’ login.
1. On the left hand side in the admin portal select groups → Shared Mailboxes
2. Select +Add a mailbox; then enter a name and email address for the mailbox
3. Select the shared mailbox and edit the members list, then ‘Add members’.
4. Select all users that you would like to be able to see this shared mailbox and save.
5. The shared mailbox will add itself automatically to Outlook 2010 and up for all members. This can take up to 30 minutes to recognise, from there the users can respond and manage mail as though it was a normal mailbox.