Flow failures due to "ErrorSendAsDenied"

[nichikan]

My flow failed to submit on 3/12 due to “You are not authorized to send mail on behalf of the specified sending account” error. The connection is my microsoft.com email account that has 'Send-As' permissions for the service account that the email comes from. We use the flow to send an email from this service account (but really from my email alias) whenever a Form is filled out. Up until 3/11 it was working successfully. I double checked the permissions for the service account and I do have 'Send-As' perms so I don't think it's an issue there. What could be wrong?

  "error": {

    "message": "You are not authorized to send mail on behalf of the specified sending account.",

    "code": "ErrorSendAsDenied",

    "originalMessage": "The user account which was used to submit this request does not have the right to send mail on behalf of the specified sending account., Cannot submit message."

Thanks in advance for the help!

[trad]

Microsoft is having issues right now.

[nichikan]

This is persisting despite the AAD outages from earlier 😞 Edited message to clarify my existing issue

[nichikan · Accepted solution]

I created a new flow using this template and was able to achieve my objective: https://preview.flow.microsoft.com/en-us/galleries/public/templates/9718c800748b4224b595f7ac29e04740...

Previously I was using "Send Email (v2)" instead of the "Send an email from a shared mailbox (Preview)" step

[mtsilbiger]

I'm seeing this today too. I hope it is resolved so I don't need to re-create all of my flows.

[v-aaz]

Same here.

[htapley]

This has been failing for me today as well. Nothing with my scheduled Flows have changed in weeks. However, they're failing at the point to send the email as another.

[v-antal]

I'm a currently experiencing the same issue. Since yesterday multiple flows are failing. These flows have sent the emails from a shared mailbox for more than 12 months without any problem

[LisaHudson]

I'm having the same issue and the solution did not work for me.  Is this a global issue?  

[ekpoleta]

I have this issue as well from 5/22/2021.  Could you please update on this?

[Monisor000]

Hi all, this error still occurs on my recent flow, is there a fix yet?

[DeeTronSEAM]

One thing to keep in mind when troubleshooting this is that for automated flows (i.e. scheduled flows) when the flow fires it runs in the security context of the co-owner who most recently edited the flow.  

E.g. User "O" creates a new automated (reoccurrence trigger) flow which contains an O365 Outlook Send an Email (V2) action which uses a connection User "O" created with their credentials. I.e. it connects to their mailbox (UserO@Contoso.com).

User "O" then shares the flow with User "C"...i.e. now it is a Team Flow and has two "Owners"....or more accurately, two co-owners, one of which is the Creator.

A week later, User "C" edits the flow so the Send Email action uses an updated Subject value.
The next time the flow runs it will fail as the "From" value and the user mailbox being accessed are not the same user & his mailbox.
I.e. the connection points to mailbox "UserO@contoso.com" but the security context of the flow run is using UserC@contoso.com.

Obviously, if the UserO mailbox has been configured to grant SendAs permissions for UserC, the flow won't error, as described, but that is a workaround/configuration outside the scope of this docUpdate request.