Can't send as shared mailbox when Show in Global Address list set to No

[Jeff Shelp]

I set up a new shared mailbox in Office 365 Admin Center and added members and also set Show in Global Address List to No, since we do not want this shared address to show in the address list.

Members of the Shared mailbox were not able to send email from Outlook 2016--yes we waited about 12 hours and no improvement.  They were able to send as from Outlook web app.

Seeing another post about problems with GAL and shared mailboxes, I went ahead and set Show in Global Address List to Yes and now users can send as from Outlook.

Is this by design?  Why is the Show in Global Address List an option with Shared Mailboxes if it disables the ability to send from them?  We need this address to not show in the address book, but have the ability to be sent from.  Is there a way to do that, something I'm missing?

[#2 · Accepted solution]

Yes, this is the expected behavior.

[#3]

Thanks for your reply, that is good to know.  How would setting "Show In Global Address List" to No be used if it prevents using the Shared Mailbox?  Why does MS provide that option?

[#4]

There's more to a Shared mailbox than just being able to use "send as".

[#5]

Hi Jeff,

as Vasil has already said that's by design. You can try to use an alternative way to send as non-default address.