Showing results for 
Search instead for 
Did you mean: 
Helper III
Helper III

Flow Suddenly Failing - "Forbidden"

Hi all. I have a complex flow created by a former IT associate; it sends an email when a project's status changes to "Assigned." It's been working for years. As of Monday, I'm receiving a 403 error:




















I am not in IT so - I'm a bit at a loss. The flow itself had not changed. What may have changed is the "from" email. It was coming from one email (let's say to From what I can tell in Outlook, oldmail might be forwarding to new email?  Or, they deleted the old one and now it's the new one? I don't know. That swap happened, and it worked on Friday and through Monday, then stopped. 


Anyways - any ideas would be appreciated. (PS - I tried putting a ; after the From email - no luck...

Helper I
Helper I

Hi @JillH ,


I would suggest you to navigate to Microsoft Office 365 admin center (Link shown as below), and make sure the "" account have all the necessary licenses, e.g. Microsoft Power Automate Free/ Office 365 Business Essentials/ Office 365 Business Premium.


If might take 3-5 mins for the Sync purpose based on my experience. If still no luck,  just to make sure account and account have the exactly same settings.


Microsoft Office 365 Admin Center: (you might need to login as admin)





Thank you! Here... is what the SysAdmin told me (since I don't have admin rights) :

"If it is sending Address only it does not need that and shared mailboxes do not get licensed."


Hi @JillH ,


'Send Email' function in Microsoft Flow use 'Outlook', for my understanding no matter if it is a shared Mailbox or a personal mail box, that account need to have a license. Would you mind to just let your sys admin give that account a license and try it out?


Shared Mailboxes can be also found under Active Users as well.





Can you try clicking on the outlook action and seeing what connection is being used.

Try adding a new connection.
This can be done by clicking on the outlook action, you should see a email address on the bottom right on the action (this is what the connection is set to)
Click on the email address and click add new

If you like my post please hit the "Thumbs Up" -- If my post solved your issue please "Mark as a Solution" to help others

Did I answer your question? Mark my post as a solution!

If you like my post please hit the Thumbs Up

Proud to be a Flownaut!

Check out my blog for Power Automate tips,
tricks, and guides

New Member

I've received the same "forbidden" error. For me, the adress from which the emails should be sent, didn't exist anymore. What worked for me was: In the "Send an email" action open "advanced options" and changing the "Sent form" field with another email adress (where i had the rights to send emails from). 


Good luck!

Helpful resources

Power Automate News & Announcements

Power Automate News & Announcements

Keep up to date with current events and community announcements in the Power Automate community.

Community Calls Conversations

Community Calls Conversations

A great place where you can stay up to date with community calls and interact with the speakers.

Power Automate Community Blog

Power Automate Community Blog

Check out the latest Community Blog from the community!

Users online (4,087)