help.mail.colostate.edu logo

CSU Logo - click to visit the CSU homepage


Authenticating with Shared Mailboxes in Office 365

Note: The documentation included on this page is targeted for departmental IT administrators and Exchange Resource Coordinators. If you have questions about the use of shared mailboxes, please contact an Exchange resource coordinator for your area.

Effective 1/29/2016, users can authenticate with shared mailboxes hosted in Office 365 with either option listed below:

  • Users who are members of the shared mailbox's permissions group can authenticate using their eName and ePassword when prompted while connecting directly to a shared mailbox from Outlook or OWA.
  • New! - Users can login to a shared mailbox using the username and password for the shared mailbox where the username (ex: demo_mailbox@colostate.edu) is patterned after the name of the shared mailbox.

Prior to this change, the username/password option was not supported for shared mailboxes. In most cases, whichever option best suits your needs should work to access a shared mailbox. However, if you manage a shared mailbox with voice mail (i.e. a UM-enabled shared mailbox), you must use the username/password option in order to access the voice mail section of OWA. The username/password option is also required if you want to connect to a shared mailbox from a mobile device. Resource Coordinators can manage passwords assigned to shared mailboxes using the "Update Shared MB Password" option available within the Resource Coordinator Tools. Please refer to the FAQs below for more information about shared mailboxes in Office 365.


Shared Mailbox FAQs

  1. Why was the change made so that shared mailboxes can now also be accessed with a username/password?
  2. Will this change break access for users who currently use shared mailboxes by way of their membership in a permissions group?
  3. What username should I use to access a shared mailbox using the username/password method?
  4. I noticed that the username (ex: demo_mailbox@colostate.edu) of the mailbox is different than e-mail address (ex: demo_mailbox@mail.colostate.edu) of the shared mailbox because it doesn't include "mail" after the @ sign. Can I just use the username as the e-mail address for the shared mailbox?
  5. How can I change the password assigned to a shared mailbox?
  6. Are shared mailboxes the same thing as secondary eID mailboxes?

Why was the change made so that shared mailboxes can now also be accessed with a username/password?

The change to assign a username and password to shared mailboxes resulted from changes to the security model implemented in Office 365. Notably, users who were members of a shared mailbox's permissions group could historically access voice mail options from OWA (O365 OWA > Mail > Options > General > Voice Mail). With the new security model, you must login to OWA as the account itself to access the Voice Mail menu. Additionally, Microsoft has indicated that CSU's practice of having non-Exchange users (typically undergraduate students) access shared mailboxes by way of their membership in permissions groups is not supported. "Not supported" in this context means that current functionality may continue to work but if a future O365 update breaks non-Exchange user access to a shared mailbox, Microsoft support will not be able to fix it.

Will this change break access for users who currently use shared mailboxes by way of their membership in a permissions group?

No, this change will not break how CSU users currently use and access shared mailboxes. Allowing access by way of a username/password simply provides CSU users with flexibility to work around constraints introduced by O365 while still supporting traditional access methods for shared mailboxes.

What username should I use to access a shared mailbox using the username/password method?

The username for a shared mailbox is similar to the e-mail address of the mailbox except that it ends in @colostate.edu rather than @mail.colostate.edu. For example, the shared mailbox "Demo Mailbox" would have an e-mail address of "demo_mailbox@mail.colostate.edu" and the username for the mailbox would be "demo_mailbox@colostate.edu".

I notice that the username (ex: demo_mailbox@colostate.edu) of the mailbox is different than e-mail address (ex: demo_mailbox@mail.colostate.edu) of the shared mailbox because it doesn't include "mail" after the @ sign. Can I just use the username as the e-mail address for the shared mailbox?

No, you should still use the e-mail address ending in @mail.colostate.edu for shared mailboxes. Sending e-mail to the username of a shared mailbox may work in some scenarios but not for all.

How can I change the password assigned to a shared mailbox?

Departmental Exchange Resource coordinators can modify passwords assigned to shared mailboxes using the "Update Shared MB Password" tool available in the Resource Coordinator Tools.

Are shared mailboxes the same thing as secondary eID mailboxes?

No, shared mailboxes and secondary eIDs are 2 different types of accounts that both happen to have mailboxes hosted in O365. Shared mailboxes are created by departmental Exchange Resource coordinators using the Resource Coordinator Tools. Shared mailboxes are assigned a permissions group, which can be used to easily grant multiple people access to the shared mailbox. Finally, shared mailbox e-mail addresses take the form of PREFIX_MailboxName@mail.colostate.edu. Secondary eIDs, on the other hand, are created by submitting a request to the CSU Help Desk and are limited to 8 or fewer characters with no special characters. Secondary eIDs are "owned" by a primary eId user and have uses beyond e-mail. E-mail addresses for secondary eIDs take the form of ename@colostate.edu.