Shared Mailboxes in Office 365

by | Dec 3, 2019 | Collaboration

Shared mailboxes are helpful in maintaining correspondence with a group of people.  Organizations often use these for centralized distribution to HR, Accounting, or IT Support.  An email is received in the mailbox and multiple people can access it and respond to it.   

Shared mailboxes in Office 365 do have some limitations, based on the licensing model, such as: 

  • Shared mailboxes are free and do not require a license, but every user that accesses the Shared Mailbox must be assigned an Office 365 license. 
  • They cannot be accessed by users with an Exchange Online Kiosk license. 
  • They can be used to store emails sent to and received by the Shared Mailbox. 
  • They can be used to store data migrated from on-premises Public Folders. 
  • Each shared mailbox can be a maximum size of 50GB; Shared mailboxes over 50GB in size need to be licensed. 
  • A Shared mailbox doesn’t have a username and password, and users cannot log into it directly. A user must sign in to his/her own mailbox and then open the shared mailbox using permissions. 
  • They cannot be used to archive emails from a user. 
  • They cannot be used for Journaling. 
  • They cannot be accessed using ActiveSync clients. 
  • Shared mailboxes do not support the Unified Messaging feature. 
  • They cannot be accessed using the Outlook client. To access a Shared mailbox on the Outlook client, you need to first configure a user mailbox that has access to the Shared mailbox. 
  • The Active Directory user associated with a Shared mailbox is always a disabled user account.

If you are planning to move to Office 365, it is recommended that you review how your organization uses shared mailboxes prior to migration.  If people are accessing shared mailboxes on a device via ActiveSync or if users are logging into the mailbox, the shared mailbox will cease to be accessible after the 30-day grace period following the migration.  Additionally, if your organization is required to journal or archive, those features are not initially available when unlicensed.  To continue to use shared mailboxes in this fashion, or to activate additional attributes, a license will need to be assigned.  Thus, licensing costs will increase based on the number of shared mailboxes in the environment. 

Do you need help with an Office 365 assessment or migration?  Peters & Associates will be your trusted partner to get you to Office 365. Email to start the conversation.  We are happy to help!