Unauthorized Post Attempt …

For the past year or so I have been using postie with great success for a website of a local association. Since the former secretary has quit and his place has been taken by a new secretary, I have been getting an “Unauthorized Post Attempt from [email protected]” error message with every post.
The user with this new address has the role of editor and the position states that editors are allowed to post. (zie screenshot in de url) I then included the email address in the list of allowed addresses, but that did not help either. I currently log in after each error message and set the post status to published, but that is not a sustainable solution.
Any help is greatly appreciated