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

[#1]

@Champnet, absolutely not!

[#2]

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@ebforum wrote:

The complete lack of an official update for several weeks is exceptionally poor in terms of professional IT service management. Such an approach makes me feel that us service users are being strung along until the Greenby e-mail solution is in place.

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You will find the ‘official update’ from last week here: https://community.plus.net/t5/Email/Microsoft-email-issue/m-p/2017289#M51880

This is likely where you will see any future updates.

[#3]

What was wrong with adding an update to Sending emails to Microsoft-owned domains such as ... - Plusnet Community? Classic tactic to start a new thread to make it look like a much more recent problem or just indicative of the ongoing chaos?

[#4]

@Tim-J wrote "But Plusnet is a tech company, not a diverse multinational."

Correction: these days Plusnet is a tech subsidiary of a multinational. My point remains. I've no doubt that Plusnet management understands the issue. They are just wringing their hands and waiting for it to become Greenby's problem.

[#5]

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@abitpedantic wrote:

 Classic tactic to start a new thread to make it look like a much more recent problem or just indicative of the ongoing chaos?

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Or even the idea that by pinning it to the top of the email board it would attract the attention of those who have not been following this particular topic?

[#6]

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@abitpedantic wrote:

Judging by the lack of posts over the last few days, I can only conclude that everyone on this forum has either lost interest or has given up on Plusnet....

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I'm still following this topic, I started it.

I've not given up on Plusnet - yet.

[#7]

Me too, @stuck , and I'm not even a Plusnet subscriber. I know, from past experience, that we won't be told all the gory details when it gets resolved, but I am just following it out of interest.

[#8]

I am still here too and there has been zero signs of progress from our perspective.

I worry the migration to Greenby will go ahead and then Greenby will say this was a warts & all migration,
what you have now is exactly the same functionality and issues as before.   Like it or lump it.

That could result in an implosion for Greenby when subscriptions do not follow as the mail platform
remains unfit for purpose.

Now Plusnet may be on the verge of a solution, but faced with a complete absence updates,
assuming the absolute worst is an exceedingly prudent position to take.

[#9]

Greenby speculations are just that.  Until the nature of the issue is understood pointing to or away from Greenby being a panacea is futile.

One needs to focus solely on why do Microsoft services accept emails when addressed individually but not when (visibly) sent to multiple addressees.  What are the differences and then why the difference in behaviour by the receiving services?

It is all the same setup at the sending end but why does Microsoft care who else the email is sent to?  Frankly it’s none of their business!!  I wonder if the user experience would be the same if addressees were bcc’d?

Unfortunately being unable to replicate the issue makes diagnosing the issue very difficult.

[#10]

@Townman said:

One needs to focus solely on why do Microsoft services accept emails when addressed individually but not when (visibly) sent to multiple addressees.  What are the differences and then why the difference in behaviour by the receiving services?

And in fact it's not that simple.  See my previous example where one day an email to a group of people was bounced by Outlook.com but not by Hotmail.  But another day, an email to the same group was bounced by Hotmail but not by Outlook.com.

Hence my suggestion that Outlook and Hotmail have slightly different scoring systems, but both giving a very high score for xxx.plus.com.  (Or both applying more stringent scoring systems).

The presence of multiple recipients perhaps then adds to the score,  Other random factors in the individual scoring systems then tip it over the threshold.

We're told that Microsoft themselves say that they they are applying higher standards to bulk senders, and the working assumption is that they are only reacting to the number of emails from .plus.com, ignoring the fact that individual xxx.plus.com accounts are not bulk senders.

Unfortunately being unable to replicate the issue makes diagnosing the issue very difficult.

Indeed.  So I may be right or I may be wrong, but it's difficult to know either way.  The fact that it occurs together with a DKIM failure is an added complication.

I wonder whether it would make a difference if you had strict DMARC instead of relaxed?  But I assume that it would be difficult or impossible to give each Plusnet user their own strict DMARC.  And I accept it shouldn't be necessary, especially as the error messages say that DMARK is passing.

https://dmarcadvisor.com/dmarc-strict-or-relaxed/

[#11]

@Townman

I find your post deeply concerning, particularly “being unable to replicate the issue”. I would expect that Plusnet has had a team investigating this for the last two months and by now have worked out exactly what is going on. Consequently, I have been naively assuming that the ongoing difficulty is finding a way of fixing the problem that doesn’t involve scrapping the sub-domain aspect of everyone’s Plusnet email address.

However, if it helps you at all, I can tell you that last week I sent several emails (with attachments) via MS Outlook (with all the recipients bcc’d) and received the usual crop of failure messages – all failures were MS-related addresses but not all MS-related addresses returned a failure message. I then sent a single email (with attachments) via Plusnet webmail bcc’d to those failed email addresses (there were 52) and, just as I have reported on several previous occasions, received zero delivery failure messages. Of course, I don’t know how many of those 52 people actually received the email.

[#12]

By "unable to replicate the issue", I assume @Townman means that the error is somewhat random and it's difficult to pin down that it always occurs in one situation, and never in another.  Which then means that it's difficult to diagnose the cause.

[#13]

@Tim-J 

My concern is that there is perhaps also an element of not managing to replicate some of the behaviour that users have been reporting in this thread. For example, in #473 (and #523) I reported that an email to xxxx@groups.outlook.com had resulted in several rejections with DMARC=Fail (as well as DKIM=Fail) but I never received any indication whether the reason for that was understood by anyone.

I expect Microsoft are delighted that "it's difficult to diagnose the cause"!

[#14]

Are we referring to multiple MS hosted addresses. Or any combination of multiple recipients?

I know that (at least) one MS mail service is accepting e-mails with multiple "To" addresses (when the multiple "To"s are not all MS hosted addresses). And being sent from a non-Plusnet hosted mail service (but using a Plusnet provided IP connection).

[#15]

Good to read others are equally appalled by the comments this issue is difficult to replicate
and it is all Microsoft's fault appears to be some form of reality denial.