From address doesn't meet the authentication requirements defined for the sender

[#1]

Certainly AWS platforms are not clean.  Our church email service is hosted on AWS and we cannot send to any Microsoft email account.  They have black balled some of the AWS IP addresses and totally refuse to review them.

Consequently our provider’s “solution” is to move us to Microsoft hosting … making Microsoft’s behaviour appear to be nothing more than a scam to drive more customers to their platform.

[#2]

I dare say our experiences differ. The AWS problems I have (historically) experienced are over HTTPS and web pages, and a lack of synchronicity betweeen AWS servers (some say 'yes', others say 'no' - i.e. content is available via one server, but not  another.)

[#3]

I have conducted a test from Plusnet's webmail service today. I sent, on one e-mail, to an Outlook.com account and another non-Microsoft account. Both recipients received the e-mail. So it seems that sending from Webmail works whereas from Outlook 365 it doesn't? Are different servers involved? Would Microsoft not see the same source of the e-mails and apply the same filtering?

[#4]

No all are the same.

All my testing has been done from Webmail; I have seen most of the errors other have reported.

• NDR in response to messages to @outlook.com BEFORE the fixes were applied, no issues since
• Some emails delivered to the junk folder during the fix period, none since
• Post Microsoft fix, marked difficulty getting email delivered to Gmail - initial test emails ae instant, thereafter black holes

I would suspect that you have a configuration issue with your Outlook365 email client.

You do not indicate which email brand you are using ... there are difference there.

[#5]

@Townman My Outlook 365's configuration was checked with a Plusnet technician when I first experienced the problem.

Please explain what you mean with "e-mail brand"?

[#6]

@ebforum Is your email 'xxxx@yyyyy.plus.com' or some other legacy address?

[#7]

It is xxxx@yyyyy.plus.com

[#8]

@plusnettony 

Does this match up with any other intel on the reported residual issues sending to Microsoft accounts, specifically involving hotmail and multiple addressees.

All of my testing from x@y.plus.com has been via the webmail client and I have not encountered the reported issues.  The inference that the email client could be a function of the user experience is a whole new can of worms!

To send from the same sender address, to the same multiple addressees using each of webmail and outlook365 and experience different outcomes ... seems quite unexpected. 

[#9]

I am happy to do any specific tests that Plusnet thinks will help.

[#10]

Forgot to say above that the rejection from Outlook 365 was the usual DKIM 550 rejection.

[#11]

@ebforum 

Pedantism is essential here - what do you mean by "rejection from Outlook 365 was the usual DKIM 550".

What is the (sent) from here and which service sent the DKIM 500 report?

From what I have seen reported around here, the only DKIM failures are coming from Hotmail where the email was sent to multiple Microsoft domain email services.

Do you mean that the email was sent from Outlook365 email client and the usual DKIM 550 rejection came from the Hotmail addressee?

In the scenarios being reported, do the other Microsoft domain email services addresses receive the email successfully?

[#12]

Hope this explains better than me!

Final-recipient: rfc822; xxxxxx.yyyyyyyy@outlook.com
Diagnostic-Code: smtp; 550 5.7.515 Access denied, sending domain zzzz.PLUS.COM doesn't meet the required authentication level. The sender's domain in the 5322.From address doesn't meet the authentication requirements defined for the sender. To learn how to fix this see: https://go.microsoft.com/fwlink/p/?linkid=2319303 Spf= Pass , Dkim= Fail , DMARC= Pass

The e-mail was sent from my Windows 11 PC using Office 365 to an Outlook.com address and another non-Microsoft address.

The same PC, using Chrome and Plusnet's webmail service worked OK.

[#13]

OK, thanks, but what is there in the email headers of the NDR?

There is a deal of suspicion that users are encountering false negatives on DKIM checking due it issues with Microsoft's own DNS service (known reliability issues).

I have asked @MisterW if he can help folks find the smoking gun showing such failures.  The above is the consequential end point arising from the possibility of either

• something being wrong with Plusnet's DKIM configuration and
• Microsoft failing to do the DKIM inspection proficiently

Given that the majority for single addressee email is getting through, one has to suspect that the second of the above has a marked bearing on successful DKIM validation.  Being able to determine if that is in fact the case is essential to profiling the issue.

[#14]

What is NDR?

[#15]

NDR = None Delivery Report.