Shared Mailboxes – Office 365

Creating a shared mailbox is simple with Office 365. Follow the step-by-step below, for the simplified process.

Per Microsoft – 

Shared mailboxes make it easy for a specific group of people to monitor and send email from a common account, like public email addresses, such as or 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 all stored in one mailbox. 

A shared mailbox doesn’t have its own user name and password. You can’t 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).

Sign in to Office 365

Click the waffle and select Admin

Expand Admin

Select Exchange

Select Recipients

Select Shared

Click +

Enter Display Name

Enter Email Address (this value must be unique) – Drop down the list to select the email domain.

Select the User(s) that has permissions to send mail from the shared mailbox. This can be changed later with advanced options

Enter Alias

Click Save

Once the shared mailbox is created, select it and click the pencil to edit the properties. Advanced settings are available.

Thanks for visiting and reading my posts. I am always looking for more ideas. Please comment or email me with what you would like to see.

Kelsey Epps Office365 MVP

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21 thoughts on “Shared Mailboxes – Office 365

  1. Ronald Buster

    Hi I created an shared mailbox through the office365 exchange properties adding a new shared mailbox. Adding 2 users as full access and sendonbehalf.

    Now I’am facing a weird problem in Outlook 2013

    When I created a new e-mail you cannot choose the shared mailbox in the from line (just manual)

    When I send e-mail from the manual inserted from the sent items from the normal account is used.

    Can you help met out.,

    Best regards,


  2. Aron Lo

    Hi.. Would like to ask if the shared mailbox need a plan assign to it ? Can it be converted from a user mailbox..?

    1. Kelsey EppsKelsey Epps Post author

      No license needs to be applied. If you have converted from a regular user account, then you can remove the license.

  3. Tony

    After creating the shared mailbox on office 365 I am not able to send mail to the mailbox from an external source. I am able to send mail internally.

    1. Kelsey EppsKelsey Epps Post author

      This could happen for a number of reasons. Use the Exchange connectivity tool to troubleshoot the mailbox

  4. Mark J

    Hi Kelsey, good post, thank you. I have an issue where I can send mail from a shared mailbox but one user out of the whole send list will not receive the mail. Even if I send a mail from the shared mailbox just to that one person they will not receive it… It seems very odd… have you come across anything like this before ?

      1. Mark J

        Thanks for your response Kelsey… This should go on a “stupid support stories” site somewhere. It turns out that this one user had set up a rule to put anything received from this shared mailbox into a specific folder… and then complained that they weren’t in his inbox. He omitted to tell me about the rule ! Patience very stretched !!

  5. Emmett Tolbert

    Kelsey. I have created the shared mailbox and given SendAs Permissions to a Security Group I created with several users. When my users send an email and choose the mailbox in the from list. It tells them “This message could not be sent. Try sending the message again later, or contact your network administrator. You do not have the permission to send the message on behalf of the specified user.” I want them to SendAs the mailbox not on behalf of the mailbox. What can I do here.

    1. Kelsey EppsKelsey Epps Post author

      Have they added the mailbox to their Outlook profile? Open the mailbox as the user with send as and have them try

  6. Taka

    Hi Kelsey,

    I have question. I have created shared mailbox but user cannot send externally to this shared mailbox. I know distriburtion group has delivery management option but share box dont.
    Do you know how to configure so external people can send email to the sharedmail box account?

    1. Kelsey EppsKelsey Epps Post author

      Is this a Shared Mailbox or Distribution group.

      Shared mailboxes are setup to accept email from external by default. If this isn’t working then click mailbox features, then Message delivery options, then change the Accept and Reject settings.

      Distribution groups, you need to go to delivery management and change it to ‘senders inside and outside of my organization’

    1. Kelsey EppsKelsey Epps Post author

      Assuming you are talking about delegate access to the shared mailbox? This has to be a local account and not a remote account such as or

      If you are talking about forwarding email from the shared mailbox to an external mailbox, this is setup on the shared mailbox. Mailbox features, mail flow and then enable forwarding.

  7. Pao

    Hi Kelsey,

    Apart from the Office 365 Exchange Administrator role, is there a specific admin role I can assign so I can delegate creation of Shared Mailboxes?


  8. Mihai Stumbea

    how long does it take before shared mailbox appear in Outlook, after you gave rights to the user for full access?

  9. Ziga Ljubic

    I have a licensing/security question. If you know the answer to it I would be more than grateful.
    We are licensing a customer with Exchange online plan 1. This license includes a service called “Exchange online protection” and on top of that we will be selling them Advanced Thread Protection, which is a USER license. Now the discrepancy question. Does the customer need to buy EXTRA EOP and ATP licenses for Shared Mailbox ?
    TechNet says:

    Shared mailboxes need to be licensed for Advanced Threat Protection. For example:
    • A company has five 5 users in Office 365. Each user has a mailbox, and there is one shared mailbox. This company will need a license for:
    o 6 seats of Exchange Online Protection (5 users + 1 shared mailbox)
    o 6 seats of Advanced Threat Protection (5 users + 1 shared mailbox)
    How can this be correct since Plan 1 and ATP are both USER licenses and we are licensing a USER not mailbox.
    Thank you and best regards


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