This browser is no longer supported.
Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support.
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(310.4, 76%, 40%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EJM%3C/text%3E%3C/svg%3E)
For some reason at random Outlook comes up wanting us to login to all the mailboxes that a user is a delegate on. They are classified as user mailboxes with either E3 or Exchange Online licenses, and not shared. It works for a week or three, and then they all want it again.
It more so seems to happen when something is changed with their login such as setting up Hello for Business for example, but mostly just happens at random. It started as soon as they and the hardware were migrated to Azure (computers are now Hybrid Azure AD Joined) through Azure AD Connect.
They have no issue with their personal account.
When I put the password back in, I select for this application only, because a while back there was an issue with selecting the Ok. Could this cause what we are seeing, or is it something with Azure AD Connect? The only difference with them are they are M365 only, they are not tied to our AD server.
Hi @Jon Mercer
As your issue is out of the support scope of OOS, to better help you, I would modify the tag "office-exchange-online-itpro".
Thanks for your understanding.
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(25.6, 67%, 12%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EJS%3C/text%3E%3C/svg%3E)
Hi @Jon Mercer
Do you have on-prem Exchange sever in your environment? Where are your users located now, all on cloud?
I see some similar issue happened in hybird environment, Microsoft Outlook connects to your primary mailbox in an on-premises Exchange server by using RPC, and it also connects to another mailbox that's located in Office 365. Outlook prompts for password and doesn't use Modern Authentication to connect to Office 365. You could ignore it if this is not the case for you.
In addition, have you tried configuring a new profile to verify the result again?
Exchange is pure cloud.
I haven't tried a new profile. It though does seem to be something with modern authentication, since it didn't happen till the users and computers where added to Azure as Hybrid Azure AD Join, which kicked in the modern authentication. It asks to apply to app only, or click ok, to register the system.
Guessing there is something with Modern Authentication that handles passwords differently then the old way, because it wasn't an issue till the computer and account were migrated.
It took a bit of digging, but verified that no one is using RPC over HTML anymore. Wanted to verify, because many a year ago, there was a 2013 SBS server with on-prem exchange, but they migrated off that a fair number of years ago, and most of the employee's accounts were created after the migration.
Hi,
Thanks for providing more information!
From server side, we may consider removing and re-adding the delegate permission for the users.
From client side, re-adding the mailboxes users have permission with, cretaing a new profile, or using Microsoft Support and Recovery Assistant to help determine the issue.
And if the suggestions above not able to solve your issue, the issue may related to o365 or azure backend, we could openning a service request to get more information as well: Get support
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(51.2, 93%, 14%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EJL%3C/text%3E%3C/svg%3E)
Did you find a solution?
Did anyone find a solution with this issue? we are having the same problem but right now we are on-prem.
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(86.4, 49%, 18%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3ENR%3C/text%3E%3C/svg%3E)
We have the same problem. But we find a solution. The problem is how we share the mailbox.
Before, we "Add an account" like this :
Now we go on Settings of this Account, and Add mailbox here :
Now, we dont have problem. But i confirm, the default problem is the Modern Authentification with an Hybrid Environment.