Shared mailboxes

A shared mailbox is not associated with an actual person; they’re generally used for generic email addresses like sales@maroonballons.co.uk. The shared mailbox doesn’t need a separate license, but users accessing the shared mailbox do need an Exchange Online license. Without a license, shared mailboxes are limited to 50 GB, but you can assign licenses to the mailbox to increase capacity. For instance, assigning an Exchange Online Plan 2 license will increase the mailbox size to 100 GB, or assigning an Exchange Online Plan 1 license with an Exchange Online Archiving for Exchange Online Add-on will allow you to enable auto-expanding archiving for archive capacity of up to 1.5 TB.