We still need your expertise and help.
We're stuck on the same point with the same error message.
Thank you in advance for your reply.
Best posts made by bastien
RE: Mail retrieval error
Thank you for this new answer.
I've changed the settings as you suggest.
And you've put me on the right track!
The call to the API is not made on HTTPS, despite the redirection...
So in my case it's a problem with the HTTP server settings!
And it works with Zimbra too.
But for the moment only in HTTP.