How to add a shared mailbox as additional account in Outlook (2022 version)

The question on “how to do this with a shared mailbox” is quite common, and the usual answer more often than not remains “add the shared mailbox as additional account in Outlook”. Doing this will expose all the “native” functionalities, including access to Inbox rules, signatures, auto-reply, add-ins, categories, proper search experience, Mail merge, and more. As a general rule of thumb – if you can do something with your regular mailbox, you can do it with a shared mailbox too, as long as it is added the “right” way. This is even needed for “advanced” features that require additional licensing, such as access to the Online archive for a shared mailbox.

Usually, when users are granted access to a shared mailbox, the Automapping functionality is utilized. This is in fact a helpful feature, as it will ensure that the shared mailbox will automagically appear in the user’s Outlook, without them having to perform any additional configuration. As is often the case however, usability comes at a price, in this case the limited set of features being exposed. So while this method might sound convenient at first, you should always check with the user on how they plan to use the shared mailbox and which features they will utilize. Then, use the Add-MailboxPermission cmdlet to grant them Full Access, while toggling the Automapping flag off.

If Automapping isn’t used, the user will have to perform some additional steps in order to access the shared mailbox. Usually, this is done by going to File > Account Settings > Account Settings > double-clicking the user’s account > More settings > Advanced > press the Add button under the “Open these additional mailboxes” section. Another scenario where you would use this method is when you are granting folder-level access instead of Full Access.

I’ve also seen quite few people go the “unsupported” route of logging in to a shared mailbox directly. Yes, this is technically possible in Exchange Online, always has been. However, it is not something that Microsoft supports and while it’s hard to find a document that clearly spells this scenario as going against the license agreement, rest assured that this is not something the licensing folks will approve of.

So after this lengthy introduction, let’s finally go over the steps to add a shared mailbox as additional account in Outlook. Unless otherwise noted, the instructions below apply to the most recent click-to-run version, which at the time of writing is Version 2110 (Build 14527.20276 on the Current channel).

To start with, hit the File menu, then under the Info pane, hit the Add account button:

You will then be presented with the (not so) new Add account dialog, which will try to help you with the process. It would be nice if there was a mechanism that would list all the shared mailboxes you have access to at this point, however this is not yet the case, so just wait for the “searching for accounts” phase to end:

Once you get to the next phase, you will be presented with a dropdown of all “detected” accounts. Do not expect the shared mailbox to appear here. Instead, place the cursor in the Email address field and type in the SMTP address of the shared mailbox you have been granted access to. This is an important/mandatory step, if you do not know the address, ask your IT folks to provide it.

Once you have entered the address of the shared mailbox, press the Connect button. Outlook will issue an autodiscover request and once it validates the address, it will present you with a credentials prompt. It’s the year 2022, so you should something similar to the below. If the prompt looks differently, you are likely using an outdated version of Office and/or Windows. Refer to the links at the end of the article for detailed steps in such scenarios.

Now, this is the most important part of the process. As you can note from the screenshot below, the credentials we are being asked to provide are for the shared mailbox account. This is not what we should do. Instead, press the Sign in with another account link, as highlighted below:

This will take you a step back to the initial login screen, where you need to enter the username. Make sure to enter your *own* UserPrincipalName here, in the format user@domain.com. Some variations might apply depending on how authentication is handled in your organization, but the thing to keep in mind is that you should be providing your own credentials!

Once you enter the username, press the Next button and complete the authentication request. Again, depending on the tenant setup, and the authentication methods configured for the given account, the steps will differ here. In my case, a passwordless authentication prompt was triggered, as shown below:

If everything goes OK authentication-wise, the process is now complete and Outlook will present you with the following dialog. As stated therein, you need to restart Outlook for the changes to take effect, so go ahead and do so at this time.

After the restart, you should see the shared mailbox as a new entry on the left nav pane, as well as under the File > Accounts dropdown menu or the File > Account Settings dialog. And, you should now have all the desired features exposed, just like you have with your own mailbox. For example, under the Manage Rules & Alerts dialog, you will now have a separate entry for the shared mailbox we just added, and you can manage rules for it:

In case you are using older version of Office and/or Windows, refer to the previous articles here and here.

This entry was posted in Exchange Online, Microsoft 365, Office 365, Outlook. Bookmark the permalink.

10 Responses to How to add a shared mailbox as additional account in Outlook (2022 version)

  1. alan says:

    Hello, I was able to add the shared mailbox as a new account. Everything seems to work fine with receiving mail, however any outgoing mail stays in the Outbox and receive message “Outlook data file cannot be accessed”.
    Is there a way to fix this?

  2. Aina Ahmad says:

    Hi, I was created a group shared mailbox, then I success to add a member team thru account admin. But, I got one member from different domain which is not registered in microsoft where I got listed an gmail member.
    So, I tried to find the solution, but I still didn’t get a clear solution to my step. So, I want to ask, actually this scenario is it allowed to add or not? Because I tried through account Admin, it cannot add different domain, the filled is auto set the require domain.

  3. Andrew says:

    This was extremely helpful for an administrative assistant who didn’t want Focused Inbox for her own mailbox, but did want it for her boss’s mailbox. I guess that’s one of the feature trade-offs for having the mailboxes ‘automagically’ added. Thanks!

  4. Juan says:

    Hi Vasil,
    Just came across this article and I can report that one of the features not enabled of a shared mailbox is the custom signature: each manually-added account in Outlook can have a separate signature set up from your personal account. For example, the purchase dept. is very happy to sign their e-mails with a collective ‘Kind regards, your purchase dept.’ while they can each have an individual signature (‘Hugs and a firm handshake – Frank’) for that warm, personal touch.

  5. Gregg says:

    Hi Vasil,
    awesome article, and easy to follow steps.

    However, I am curious about your statement:
    “As is often the case however, usability comes at a price, in this case the limited set of features being exposed. So while this method might sound convenient at first, you should always check with the user on how they plan to use the shared mailbox and which features they will utilize. Then, use the Add-Mailbox Permission cmdlet to grant them Full Access, while toggling the Automapping flag off.”

    I have spent some time searching online, and cannot really find anything missing in a shared mailbox that is available in a standard user mailbox. A few things that people came up with, appear to in fact still be available with a shared mailbox, you just have to modify a few settings.

    Can you possibly list the features that are disabled or missing? It would be awesome to know these differences so we can ascertain what features our clients need that will not work or be crippled in the “standard” way of adding users to shared mailboxes.

    Thanks again for a great article, and look forward to you assistance with this query.

    • Vasil Michev says:

      It’s not about missing functionality depending on the mailbox type, but about missing functionality depending on the way you add the (shared) mailbox in Outlook. Take Inbox rules for example, you can use them with both user/shared mailboxes, but Outlook only exposes this functionality when adding the shared mailbox as additional account, not when it’s automapped.

      I’m not a native English speaker, so what sounds clear in my head is sometimes confusing to others, sorry 🙂

      • Gregg says:

        Hey Vasil,
        all good, and totally clear. Just was curious about what might be missing with the two different approaches. Will have to look at rules and see how it differs. Thank you.

      • Vanessa says:

        Hi Vasil, great article but I do have a follow up question? if I was given a full access to a shared mailbox and it was auto mapped, can I still perform the manual set up of adding it as additional account? Appreciate your immediate response.

        Thanks

        • Vasil Michev says:

          You can, but best ask you IT staff to remove the automapping in order to avoid any issues down the line.

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