Unable to send emails to certain addresses

[#1]

Hi,

I am getting bounced emails sending to certain addresses with error as follows:

Reason: A message that you sent to the following recipient could not be delivered due to a permanent error. ** The remote server ?? responded with: ** sales@rothervalleyoptics.co.uk ??:?? This message was created automatically by mail delivery software on the server

I can send fine to my own gmail address - just other addresses that bounce. What is going on here?

[#2]

I too have seen very similar error messages when trying to send emails to two French friends, one at userID1@neuf.fr and  the other at userID2@sfr.fr both of which have worked properly in the past. Have some spam- or virus-detecting procedures been made more aggressive and now give false positives?

[#3]

Hello @kdiment, thanks for getting in touch with us. 

I'm sorry you've had some trouble with sending across emails via your Plusnet email address, everything looks okay from this side. Are you having any trouble sending emails to any other email address? If not and it's just those two I'd recommend checking spam/filtering settings, and whitelisting the email addresses if possible. 

Let us know if you need further assistance. 

[#4]

Far be it from me to point out that spam/filtering settings apply to INCOMING mails - not outgoing. So just exactly what are you suggesting we change?

[#5]

Good call on the not so helpful advice on SPAM settings!

Is this an on-going issue?

If yes, are you sending as @youraccount.plus.com or @yourdomain hosted by Plusnet?

Are there any error codes with the rejection message?

Is there anything "interesting" in the rejection email headers?

[#6]

So - technical support finally tracked down the problem. Apparently my static IP address had been placed on a PBL (Policy Block List). Head to https://www.spamhaus.org/query/ip/"your IP address". If on the list you can asked to be removed.

Looking at the reasons why I my IP address would be on this list - the only one I could identify with was logging onto the email server without authentication settings. Exactly what the Plusnet email help pages tell you to do!! I had an Outlook client that was configured this way and can only concur that this caused the issue. Have yet to conclusively prove it.

[#7]

Arguably the help pages need to be updated - it’s something which has been requested.

If connecting to the SMTP server from the Plusnet network authentication is not essential. Such was fine in the days of fixed PCs always attached to the same network connection point. Of more recent times authenticated connection to SMTP servers is normal and to be expected as best practice. Whatever authenticated connection is essential for off network access to any SMTP server.

Many receiving email environments these days are very sniffy about accepting emails submitted via unauthenticated SMTP connections in order to mitigate the propergation of spam.

[#8]

The outlook client that had the authentication off is running on my home PC and only connects via my plusnet connection. So within the rules. What I cannot work out is why my IP address was put on this blocking list. Indeed - in order to know my IP address to put me on the list it must have been from my home plusnet connection.

[#9]

If the mail service receiving the email sees enough emails from your IP address and is so prissy having recognised that the relay was not authenticated, then it is the submission IP address which gets black listed.  It matters little if you or I think that the connection to the PlusNET relay is or is not within the rules being unauthenticated, it is the receiving domain which makes the decision on if it will or will not accept the sent email, not the sending service.

There are similar scenarios to mitigate spam submission via compromised account credentials, again profiled against the submission IP address.

You have not identified the domain which rejected the email, nor indicated the volume of emails sent to that domain ... which might illuminate why the IP address had been black listed.

[#10]

Hi @bigtench 

I've been kicking this issue (and another) around with tech support.  Is it possible that there are details presumed here which are not correct?

You were not explicit about the email address you were sending from, nor the SMTP server via which you sent the emails which failed.  In that omission it has been inferred that you sent from @youraccount.plus.com via SMTP relay.plus.net to @rothervalleyoptics.co.uk

The background investigation arising out of my questions has identified a rejection message from rothervalleyoptics.co.uk reporting a SPF hard failure on an email sent from your forum profile email address.  Note that these headline were reported to me, not the actual details, I only have scant information.

Given that all @*.plus.com domains are configured with soft fail SPF, that somewhat suggest that the inferences made in offering advice might have been flawed and that the issue lays somewhere else.  For example the sending email address does not belong to Plusnet, but your are using the Plusnet SMTP relay service which is not included in sending domain's permitted SMTP server list.  The receiving server bounced the email based on it failing to comply with the SPF specification for the email address used.

Are you by chance running your own email server and SMTP service, rather than using Plusnet as a smart relay?

[#11]

I have no idea what 'SPF' is.

Anyway - the emails were sent from my plusnet account via the relay.plus.net server. However I may have had incorrect port settings for the SSL stuff. It used to work - but I have now changed to the recommended and it works.

I also had the same issues sending to @sympatico.ca and @yescartridges.co.uk.

It appears people also had issues sending to me.

Things appear to be working again so far after the PBL thing.

[#12]

Actually - it is not working - and you have closed my case 209920392.

Here are the contents of the bounce back. I replaced the recipient with xxxxxx

Response email:

Subject: Mail delivery failed: returning message to sender

      This is an automatically generated Delivery Status Notification.     

Delivery to the following recipients failed permanently:

   * xxxxxxxxx@sympatico.ca

Reason: A message that you sent to the following recipient could not be delivered due to a permanent error. ** The remote server ?? responded with: ** peter.wood@sympatico.ca ??:?? This message was created automatically by mail delivery software on the server .

Attachment 1:

Reporting-MTA: dns; avasout04 [212.159.14.19]
Received-From-MTA: dns; [IPv6:::ffff:192.168.1.105] [84.92.121.206]
Arrival-Date: Fri, 22 Jan 2021 16:35:24 +0000

Final-recipient: rfc822; xxxxxx@sympatico.ca
Diagnostic-Code: smtp; 550 Message rejected

Last-attempt-Date: Fri, 22 Jan 2021 16:35:26 +0000

Attachment2:

Received: from [IPv6:::ffff:192.168.1.105] ([84.92.121.206])
by smtp with ESMTPSA
id 2zP8lUaPxrXCc2zP9lyGCR; Fri, 22 Jan 2021 16:35:24 +0000
X-Clacks-Overhead: "GNU Terry Pratchett"
X-CM-Score: 0.00
X-CNFS-Analysis: v=2.3 cv=Q+xJH7+a c=1 sm=1 tr=0
a=i+4rrMvQlyiF9ZGJ8WH7DQ==:117 a=i+4rrMvQlyiF9ZGJ8WH7DQ==:17
a=xqWC_Br6kY4A:10 a=HpEJnUlJZJkA:10 a=_6GpL_ENAAAA:8 a=3pfoXPgmLRG-25sUmTkA:9
a=QEXdDO2ut3YA:10 a=xupg4knwUDYA:10 a=yMhMjlubAAAA:8 a=SSmOFEACAAAA:8
a=Sj8Yi0s8SOOieITW52cA:9 a=2_7Jg8NoFSUalEMR:21 a=gKO2Hq4RSVkA:10
a=UiCQ7L4-1S4A:10 a=hTZeC7Yk6K0A:10 a=frz4AuCg-hUA:10
a=pHzHmUro8NiASowvMSCR:22 a=xoEH_sTeL_Rfw54TyV31:22
X-AUTH: bigtench+vic@:46500
MIME-Version: 1.0
To: xxxxxxxxx <xxxxxx@sympatico.ca>
From: Vic Kawciw <vic@bigtench.co.uk>
Subject: Test email
Date: Fri, 22 Jan 2021 16:35:24 +0000
Importance: normal
X-Priority: 3
Content-Type: multipart/alternative;
boundary="_C7C01151-F14E-4A6C-9056-8A8A72868178_"
X-Antivirus: Avast (VPS 210122-2, 22/01/2021), Outbound message
X-Antivirus-Status: Clean
X-CMAE-Envelope: MS4wfIBxVPm2SDO8KDprBwIvspFEIdDI2IGgtHOKvul5ObzfJVTjS6l3zqtXWmZ4NV1AHt2VeYOxxqZqKiQL/KS7LvDgSJm2Buu1vOajyoAfdH/X1sP1w+Uw
1J+81LFIm9momCXLiUUH1vem3Ldf6/n0f7TGUr9hxkEX6fjc1SUV6edWm9mFO9u3gVn7HGB6VutCcw==

[#13]

Thanks for getting back to us @bigtench 

Apologies that your ticket was closed. I've passed on what you've said back to our NetOps team for further investigation.

I'll provide an update as soon as we know more.

[#14]

@bigtench 

Anyway - the emails were sent from my plusnet account via the relay.plus.net server

But as @Townman suggested above, they are not being sent from a plusnet email address.

From your bounce information, that is being sent from a bigtench.co.uk address.

Looking up the bigtench.co.uk domain, it is hosted by namesco and the SPF record says that mail for that domain MUST be sent via the lcn.com servers

Your SPF is showing as

v=spf1 include:spf.lcn.com -all

what that means is that email from your bigtench domain should not be sent via other servers and and if it is, then it should be rejected by the receiving server. So when you are sending via the plusnet server ( relay.plus.net ), any receiving server that is configured to check for SPF will reject it. THe only reason you are able to send any mail is that most servers do not stick rigidly to the SPF rules. It would appear that some you send to do!

You really need to do 2 things, 1) change your SPF record to include the plusnet relay servers and 2) change the '-all' to '~all' , which changes the HARDFAIL to a SOFTFAIL

For details on SPF have a look here https://en.wikipedia.org/wiki/Sender_Policy_Framework

If you only send via the plusnet servers then I would suggest your SPF record should be

v=spf1 include:_spf-internal.plus.net include:_spf-internal2.plus.net ~all

if you possiblly send via the lcn servers as well then it should be

v=spf1 include:spf.lcn.com include:_spf-internal.plus.net include:_spf-internal2.plus.net ~all

[#15]

OK - so my bigtench.co.uk domain is indeed hosted by LCN - and I have configured email forwarding to to my plusnet email. This has been setup this way for years -  the idea being that I can just point my domain email to whichever provider I am with. It has only now become an issue. I do not use LCN servers at all - just the forwarding. BTW I have 'SRS' enabled for the forward.

So the question is how on earth do I change the SPF information for outgoing mail in an email client such as Windows mail or Outlook or GMail on my phone?