Shared and group mailbox addresses not appearing in "From:" field

Not applicable

The Problem:
In Outlook for Office 365 Desktop - when creating a new e-mail from a shared or group mailbox, then clicking on the From: dropdown - I can only see the option to send from any accounts that are setup; not from the shared and group mailboxes themselves. I can select Other Email Address... and then select the mailbox I want to send from, but from what I understand from Microsoft, once I've done this at least once, that mailbox should be available in my dropdown; it's not. To have to go into the address book each time is too many steps and not everyone has the patience to just type the e-mail address to send from.

The current setup and what works:
It took a bit to get working, but I can send (with the workaround mentioned above) and receive from my shared and group mailboxes; both desktop and online. Further, when replying to an e-mail received in a shared or group mailbox, the user replying will have the mailbox's address set as the default address in the From: field. 

Now, the reason I say it took a bit is because in the Exchange Admin Centre I had to assign myself both Full Access and Send As permission in mailbox delegation for the shared mailbox, and both Send As and Send on Behalf permission in group delegation for the group mailbox; otherwise I'd get send permission errors. 


Solutions I've tried or read about:


  • Tried, different combinations of delegation permissions: no change.
  • Tried, recreating the shared mailboxes in 365 Admin: no change.
  • Tried, recreating the shared mailboxes in Exchange Admin Center: no change.
  • Read about: removing automapping and adding the shared mailboxes as accounts instead (not sure how this works with group mailboxes) but seems this solution is not supported by Microsoft and feels like too many steps to get at a solution. Further, potentially doesn't address issues with mailmerge unless we start creating additional Outlook profiles; again, too many steps. Reluctant to try.

Expected behaviour:

So in light of how easy I believe this should be to setup and use, my expectation is that any user assigned to a shared or group mailbox - and setup with the ability to send as that mailbox - should be able to create a new e-mail and select the mailbox that they want to send from in the From: dropdown.


Note: It's interesting to note here that at some point in my testing this out, I was able to get at least one group mailbox to appear in the From: dropdown list but without (I believe) changing anything, it went away.


The Ask:
Is there anyone out there who has had similar issues who has found a fix or reasonable workaround that makes it easy for the user?

8 Replies
best response

Hey @Deleted,


I worked at a large IT services provider who did Exchange and Office 365 for tons of customers, so I have dealt with this type of complaint/issue allot.


I can tell you 99% of the time, after digging into these issues extensively with the client, it would come down to how the email addresses were configured in the outlook client. It looks like you have tested allot of options, and when I first read the title of your email, my first thought was "I bet you he is just having it automapped, and has never actually created the shared/group mailbox as an additional mailbox in the account."


So why it would be work, I would give that a try. Normally having the account actually added as an additional mailbox, rather than just mapped in, seems to help. I would try this on just one account. You may not even have to remove the auto-mapping, but just go through the process of adding an additional mailbox. Try the "manual steps" from here -


Once you have that in, restart your outlook, and see if when it comes back online you have the mailbox in the from field.




A second thought on how you can "confirm" this is outlook and not permissions.


If in OWA, you can open the shared mailbox (click on your name in the top right, open additional mailbox, type in the shared address). If that opens a new mailbox and you can send a mail from there, then 100% your permissions and setup are right. All you have left is your outlook configuration.



There are two methods to "add" an entry to the From menu. The first one is to add the mailbox as additional account in Outlook, which exposes the full functionality, and is my preferred method to work with them. You can only do this for Shared mailboxes, not Group ones unfortunately.


The second method is sending at least one message via the From -> Other E-mail address -> From -> Selecting the object from the GAL. Depending on the permissions you have, and what you have added to the profile, you can either Send As or Send on behalf of. Once a message is sent successfully, the entry *should* appear under the From dropdown menu, with a small "x" next to it. A quick test on my current version of Outlook however does NOT add it, like it did previously. So it might be a change/regression introduced recently, which I will probe few folks about (version 1808, build 10730.20205 for the record).


In no case the entry will be automatically be populated based upon permissions, this is not how it works.

Understood Vasil and that validates what I already knew. Problem is that the second method you suggested (which I already tried) did not work as expected. However, adding the shared mailbox as an account fits the bill until I turn on "Coming Sooon" in Outlook. When I do that, the accounts don't appear; even though other accounts that I do have setup, remain.

Thanks for the feedback.  Adding the shared mailbox as an account fits the bill until I turn on "Coming Soon" in Outlook. When I do that, the accounts don't appear; even though other accounts that I do have setup, remain. I suspect this will be addressed in the final release.

We recently started to experience this as well.  For about a few months things were working then a recent build in Outlook broke the expected ability to select the Shared Mailbox in the FROM field on new emails.  Nothing seems to work to get this functionality back and Microsoft's official documentation still shows that its supported using the traditional manner (add the email once to the FROM field manually and then see it as a choice from there on out)

I am experiencing the same too. It should work with the automapping and NOT the "add as additional mailbox" method. Is there a User Voice for this so we can make Microsoft notice it?

Sorry if I'm late to this thread, but I'm despearatekly trying to find an answer to a related problem, that being when I add 'Additional Mailboxes' I never get the "From button" to show up, only the "Bcc" no matter how many we add, anyone seen this issue before?@Manou2295