User account or mailbox does not exist.

[Anonymous]

I created a simple email test flow within a Sharepoint Library. When an item is entered into the library and email is generated and emailed to three people who have valid Office 265 mail accounts. Most of the time the flow works; however, every now and again it will fail with the error "User account or mailbox does not exist.".

This has been happening on and off since December. Microsoft Support took a look at it but never resolved it. I want to put something similar in production, but have not because of this issue.

[v-yamao-msft]

Hi mporreca,

To test this issue, I create a flow to send an email when a file is created in SharePoint library. In the To field, I enter 3 email addresses who have valid Office 365 mail accounts.

Then I upload files to the library to run the flow for several times, seems that the email can be sent to all the three email accounts.

So I am not able to reproduce this issue on my side. How long has your flow been running? Could you show me a screenshot for the detailed error message?

If possible, please provide your Flow Id for a further investigation.

Best regards,
Mabel Mao

[Anonymous]

Here is the activity where you can see that they run some times, but then stop running with error at other times:

Here is one that failed:

Here is the error:

[Anonymous]

How do I find the Flow ID?

[v-yamao-msft]

Hi mporreca,

Thanks for sharing with us the screenshots.

This issue might be a SharePoint issue. It is possible that some users’ information has not completely synced down from AAD to SharePoint, resulting in the issue you are now experiencing. If sufficient properties are not yet synced down to SharePoint, then there is no efficient way to resolve this problem in the Connector. The good news is that this problem should correct itself once the users’ information syncs down to SharePoint. However, you don’t have control over when the information gets synced from AAD to SharePoint. The process that performs that sync is part of SharePoint Online’s infrastructure. So you might have to wait for the sync to occur. Once the user’s information synced down successfully, your flow will run as expected.

Best regards,
Mabel Mao

[Anonymous]

How can something from Sharepoint not sync since December?

Why does it work and then not work if something is not Synced from Sharepoint?

How can i get sharepoint to sync what ever is missing?

How can it be missing a SharePoint email account when email resides in Exchange?

I don't understand how this can be  sharepoint issue and I'm about ready to give up on Microsoft Flow because it is unreliable. It can't even issue a simple email!!! I'm even using one of the templates they advertise in the Microsoft templates!!! And no one from Microsoft has helped me!

The emails have worked, but then stop, then start, then stop. It's been going on since December 2016. And all email accounts have ben in existance for years! Luckily I have this just working on our own departmental Sharepoint library so we are used to it working sometimes and other times not working. But I am getting pressure to roll something like this out to another department. I've been telling them that Microsoft flow is unreliable for sending emails from SharePoint lists and library.

[Anonymous]

How many MONTHs do I have to wait for this to sync correctly?

[Anonymous]

Its finally working, but every once in awhile (maybe once or twice a month) the flows fail with the same error message. So it has gotten better without any changes on my end.

[Anonymous]

I'm having the same issue. Works for a long time and then all of a sudden boom it fails with mailbox doesn't exist. I go in and manually rerun the job and it works. Any thoughts?

[Anonymous]

I get this too, did anyone find a resolution?