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

[#1]

@plusnettony 

You have been quite responsive on other issues so what can you tell us about this one? The situation is perfectly encapsulated in post #681. It has been going on for over 3 months and, as far as I'm aware, Plusnet has not had the decency to provide any update for over 10 weeks. Is Plusnet making any progress in resolving the difficulties with the several email providers mentioned in @PhilipHeyes post?

[#2]

So Plusnet, what is the official position with this serious issue?

Clear official updates are needed for both Microsoft domain e-mail and iCloud e-mail issues.

The lack of clear updates does nothing for the credibility of Plusnet! Asking for such updates is only reasonable.

[#3]

I'm just wondering if this little hiccup - https://community.plus.net/t5/Email/Do-PlusNet-have-a-data-breach/td-p/2022091 is why other mail platforms have been blocking PN's mail servers, i.e. it has been happening for a while, but not targetting Plusnet customers, because whoever is behind it knows/knew that it would be spotted by a few technically literate people on here, and passed back to the business?

[#4]

For whatever reason, the world that remains accessible to Plusnet users continues to shrink.

Reporting-MTA: dns; avasout-ptp-004 [84.93.230.250]

Received-From-MTA: dns; xxxxxxxxx

Arrival-Date: Sat, 27 Sep 2025 23:05:47 +0100

Final-recipient: rfc822; xxx@xxx.co.uk

Diagnostic-Code: smtp; 550 Rejecting due to poor sender reputation: 84.93.230.250

I’ve never had a problem with this recipient before. I re-sent the email this morning and it didn’t bounce, presumably because it went via a different Plusnet server that hasn’t yet been blocked by whoever is hosting the recipient’s email.

[#5]

@Townman 

Getting on for 50% of my emails are now being rejected because Plusnet servers are blacklisted.

Here is an example from this morning, an email sent to just one person.

Reporting-MTA: dns; avasout-peh-004 [212.159.14.20]

Received-From-MTA: dns; xxxxxx

Arrival-Date: Mon, 29 Sep 2025 11:34:54 +0100

Final-recipient: rfc822; xxxxx@hotmail.com

Diagnostic-Code: smtp; 550 5.7.1 Unfortunately, messages from [212.159.14.20] weren't sent. Please contact your Internet service provider since part of their network is on our block list (S3150).

You can also refer your provider to http://mail.live.com/mail/troubleshooting.aspx#errors.

etc

Surely every Plusnet user is suffering similarly? Don't Plusnet find @PhilipHeyes list in #681 embarrassing? Is there any hope that this disastrous situation will be resolved any time soon?

[#6]

There always has to be hope!

@James_B 

[#7]

The silence suggests what remains of Plusnet's email team are more focused on Jobserve than this forum.

[#8]

It doesn't really - the individuals doing the hard work aren't forum staff.

[#9]

Perhaps you have not run business divestment programmes, a huge concern is having your best and most needed staff turn up in your office mid afternoon on a Friday and say here is my notice, I shall be out of here at 5pm today and I have secured a new job that starts  9am on Monday, good luck folks and farewell.

[#10]

Are you feeling OK, @PhilipHeyes ? Your posts are becoming more bizarre by the hour.

[#11]

I hope this is in the right thread.

So I am helping out at my local Church, they aren't the most tech savvy group of people and have come to me for help.

This is the problem as best as I can understand

They are using outlook (I think they said a new version) and have a plusnet email address so user@user.plus.com, their email seems to be working fine until they send out a email to 4 or 5 people at once, everyone gets theirs except a Hotmail user, they said when the email gets rejected it says email failed permanently. If they send the email directly to the Hotmail account it seems to send fine, it's only when it's part of a batch.

I have changed their outgoing email to use port 587 and encryption method starttls and to use the same settings as the incoming server.

Thanks in advance

[#12]

What you describe is the problem of this thread & we suffer the exact same i.e. in any message sent to multiple destinations. all the hotmail / msn / outlook / live etc emails of Microsoft reject with DKIM=FAIL in the attached error file of the rejection message 

What we also see is an individual email be rejected where the Plusnet outbound server is on the block lists of destination ISP or email operators iCloud / Microsoft / Talk Talk & Tiscali.  Again this is seen in the error file attached to the rejection email.

We also always use encrypted and authenticated connection to the email servers as this is best practice, and means you do not need to be on a Plusnet internet connection to send / read your emails. but this is not the solution to this on going email delivery failure problem.

This has being going on for months & progress has been zero, in fact the situation is getting worse with more and more of Plusnet's outbound email servers being blocked by email operators.

[#13]

in fact the situation is getting worse with more and more of Plusnet's outbound email servers being blocked by email operators.

Wrongly!

[#14]

You describe Microsoft’s problems precisely.

Email the individual email address and Microsoft does not have a problem, include that email address with a few others and their service spits out its dummy and throws all of their toys out of the pram.  Childish behaviour in the extreme.

Microsoft is notorious for such behaviour - my church has their email service on AWS and we cannot send emails to any Microsoft user - I have to use my Plusnet account.  Microsoft has refused to address that problem and the church is being forced to change hosting providers.  It helps that they use a domain name.

This problem remains under investigation with Microsoft.  You do not need to change anything, there is nothing you can do to mitigate this issue other than follow the advice elsewhere on this forum - email MS users singularly.