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Incoming email being rejected...

teapot
Team Player
Message 117 of 117

Hi,
I'm using Pipex DSL email and processing Microsoft Office Pro 2016.


Using Outlook, I have one important email sender who, suddenly is unable to send emails to my email address, it has been working for a long time.


The error - 503 Bad sequence of commands.


I have made various changes to my email settings, I believe they are correct and up to date. The sender has spoken to his support and also believes his system is correct and up to date.
This error only occurs with this sender who lives in France.

Any help and advice would be very useful. Thank you.

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116 REPLIES 116

Message 81 of 117

Hi delwynh, they won't investigate each example without the mail header sending and receiving mail address and the bounce message. If you haven't already send the information to me via personal message.

 

Ady


Please log in to My Account if you need to view or pay your bill, manage boosts and track your usage. From My Account you can also check your connection and test your line for any issues in the Service Centre.


Message 82 of 117

@delwynh wrote:

@Ady-TalkTalk  has the additional information I provided on this issue been passed on to the team?

 

That is, it started on Jan 6th or 7th when talktalk seems to have made some change to the incoming mail routing for the dsl.pipex.com domain, and for both myself and the OP the messages being rejected are from Ionos/1and1 senders.

 


Ah. So this thread isn't about the (all to frequent now) issues of the mail service becoming unusable for a few hours at a time?

 

I (well,my wife...) has a problem trying to mail a 1and1 address (and address whose MX record points at mx00.1and1.co.uk and mx01.1and1.co.uk). This is a permanent problem. They can't ever mail her and she can't ever mail therm.

 

Here's a recent bounced message when I was testing:

 

====================

This is an automatically generated Delivery Status Notification.

 

Delivery to the following recipients was aborted after 0 second(s):

 

     * xxx@nillcottage.co.uk

 

Reason: The following message to xxx@nillcottage.co.uk was undeliverable.The reason for the problem: 550-Requested action not taken: mailbox unavailable

--------------------
Reporting-MTA: dns; cmout2mk [212.74.114.24]
Received-From-MTA: dns; benuc.lacknet [92.0.128.161]
Arrival-Date: Sun, 26 Jan 2020 20:37:07 +0000


Final-recipient: rfc822; xxx@nillcottage.co.uk
Diagnostic-Code: smtp; 550-Requested action not taken: mailbox unavailable

Last-attempt-Date: Sun, 26 Jan 2020 20:37:07 +0000

====================

 

(mail addresses edited).

 

Note that this message was actually sent at 21:08:21 - the clock on cmout2mk is ~30 mins slow (which no-one seems to care about).

 

 

 

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Message 83 of 117

@Ady-TalkTalk  has the additional information I provided on this issue been passed on to the team?

 

That is, it started on Jan 6th or 7th when talktalk seems to have made some change to the incoming mail routing for the dsl.pipex.com domain, and for both myself and the OP the messages being rejected are from Ionos/1and1 senders.

 

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Message 84 of 117

Hi Teapot, I've sent a chaser as there's been no update on the ticket yet. 

 

Ady


Please log in to My Account if you need to view or pay your bill, manage boosts and track your usage. From My Account you can also check your connection and test your line for any issues in the Service Centre.


Message 85 of 117

Any news please?

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Message 86 of 117

...and cm7nec would appear to be cm7nec.talktalk.com, given:

 


[parent]: host cm7nec.talktalk.com 79.79.79.78
Using domain server:
Name: 79.79.79.78
Address: 79.79.79.78#53
Aliases:

cm7nec.talktalk.com has address 62.24.138.17
cm7nec.talktalk.com has address 62.24.151.225
Host cm7nec.talktalk.com not found: 3(NXDOMAIN)

although it is worrying that the DNS servers do occasionally return that NXDOMAIN error...

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Message 87 of 117

Here's a message as seen by someone who sent a mail to my wife and had it bounced.

[Email addresses edited to protect the innocent.  The original email address was correct]

 


From: Microsoft Outlook [mailto:MicrosoftExchange329e71ecxxxxxxxxxxxx41109e@TH2.onmicrosoft.com]
Sent: 23 January 2020 16:32
To: Orig Sender
Subject: Undeliverable: RE: Evaluation


Delivery has failed to these recipients or groups:

'My Wife'
The e-mail address you entered couldn't be found. Please check the recipient's e-mail address and try to resend the message. If the problem continues, please contact your helpdesk.

The following organization rejected your message: cm7nec.

 


Diagnostic information for administrators:

Generating server: CWLP123MB1971.GBRP123.PROD.OUTLOOK.COM

my.wife@dsl.pipex.com
cm7nec #<cm7nec #5.1.1 smtp;550 5.1.1 ufOeiYaZVQiTy Recipient Undeliverable (TT512)> #SMTP#


 

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Message 88 of 117

Hi teapot, it's not yet been picked up by the email team. I've sent a chaser for you.

 

 

Ady


Please log in to My Account if you need to view or pay your bill, manage boosts and track your usage. From My Account you can also check your connection and test your line for any issues in the Service Centre.


Message 89 of 117
Any further news on a solution to this problem, 3 working days have elapsed?
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Message 90 of 117

Gondola, thanks for your replies.  I'm sure you are correct that the changeover to use mx.talktalk.net as the MX for dsl.pipex.com is in preparation for the migration of the pipex mailboxes to the new platform.

 

Moreover it seems fairly clear that the problem both myself and the OP are experiencing with Ionos/1and1 senders is associated with this change.

 

However, it doesn't get us any closer to figuring out why messages from these senders are being rejected.  Someone needs to examine the SMTP logs on the talktalk server.

 

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Message 91 of 117

...yes read the headers from the bottom up for each Received From: instance.

 

The talktalk.net server is cm9gb1 which is one of the talktalk servers and exactly what I'd expect from the current MX lookup for dsl.pipex.com. 

 

The talktalk.net server seems to be transferring the message to the tiscali MX server for reply to the message session and delivery to the pipex mailbox. 

 

My take on all this is it's to make sure when the pipex mailboxes are 'switched' on the new platform that there is no DNS propagation delay problem.  The talktalk.net server will deliver all mail without fail to the mailbox on the Open-Xchange platform.  i.e. there'll be no mail delivered to the old pipex mailbox because adequate time will have been allowed for all DNS's to be updated.

GondolaVolunteer 2017-2021

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Message 92 of 117

When I say talktalk, I mean any of the talktalk owned entities including pipex and tiscali.

 

Before 6th Jan the first talktalk server is cmsmtp, after 6th Jan it is mx.talktalk.net which forwards onto cmsmtp.  I have highlighted the change in bold.  Thereafter they are the same, excepting the exact mk-inbound and mk-delivery servers which have always varied.  The headers should of course be read from the bottom up.

 

Before 6th Jan:

 

Received: from mk-inbound-2.mail.uk.tiscali.com ([212.139.137.162] helo=cmin2mk)
by mk-delivery-4.b2b.uk.tiscali.com with esmtp (Exim 4.69)
(envelope-from <redacted>)
id 1inSKE-000G7c-JN
for redacted@dsl.pipex.com; Fri, 03 Jan 2020 19:09:34 +0000
Received: from <redacted> ([xx.xx.xx.xx])
by cmsmtp with SMTP
id nSKEiHExVynTBnSKEiyYsg; Fri, 03 Jan 2020 19:09:34 +0000

 

After 6th Jan:

 

Received: from mk-inbound-1.mail.uk.tiscali.com ([212.139.137.161] helo=cmin1mk)
by mk-delivery-1.b2b.uk.tiscali.com with esmtp (Exim 4.69)
(envelope-from <redacted>)
id 1itryt-0005XC-DA
for redacted@dsl.pipex.com; Tue, 21 Jan 2020 11:46:03 +0000
Received: from cm9gb1 ([62.24.139.126])
by cmsmtp with SMTP
id trvfimenBt1cLtryhiKAdM; Tue, 21 Jan 2020 11:45:51 +0000
Received: from <redacted> ([xx.xx.xx.xx])
by mx.talktalk.net with SMTP
id trygiYr1nd6fPtrygilvjg; Tue, 21 Jan 2020 11:45:51 +0000

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Message 93 of 117

...you said it was talktalk but showed the helo command as responded to by the MX tiscali server in each case:

 

Received: from mk-inbound-1.mail.uk.tiscali.com ([212.139.137.161] helo=cmin1mk)
by mk-delivery-1.b2b.uk.tiscali.com with esmtp (Exim 4.69)
(envelope-from <redacted>)

 

Example headers from before 6th Jan:

 

Received: from mk-inbound-2.mail.uk.tiscali.com ([212.139.137.162] helo=cmin2mk)
by mk-delivery-4.b2b.uk.tiscali.com with esmtp (Exim 4.69)
(envelope-from <redacted>)

 

Is that still what happens now?  When I look at a check it's the cm8nec mx.talktalk.net ESMTP server responding.

GondolaVolunteer 2017-2021

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Message 94 of 117

All I can say is that received headers prior to 6th Jan were identical for Ionos and non-Ionos senders.  After 6th Jan the first hop inside talktalk is now mx.talktalk.net.  Since that date I can't receive any email from Ionos senders, so I have no headers to go on!

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Message 95 of 117

...send a mail message from another mail service provider. See what header that produces. But you're saying that the detail you gave before wasn't from Ionos mail...so another red herring / wild goose chase...

 

Unfortunately I don't have access to a pipex domain mailbox to test myself.

GondolaVolunteer 2017-2021

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Message 96 of 117

 


@Gondola wrote:

Based on your email header detail, yes I suspect Ionos are using an out of date DNS lookup.


The headers I posted were just a comparison between the headers on messages successfully received prior to and after 6th Jan to show that the pipex MX record appears to have changed around that time - neither of these headers were from Ionos senders.

 

If you still think this is the problem, how can we prove or resolve it?

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Message 97 of 117

Hi delwynh 

 

Based on your email header detail, yes I suspect Ionos are using an out of date DNS lookup. The routeing of the mail message seems to be the most likely reason for the unusual bounceback error. 

 

If you use MX toolbox to look up the MX record for dsl.pipex.com you'll see what I mean.

GondolaVolunteer 2017-2021

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Message 98 of 117

@Gondola, thanks, glad you saw it.  It took quite a while to create and I don't have a copy so I am hoping a moderator can remove it from the spam filter.

 


The Ionos lookup appears to still link first to the Tiscali MX servers before reaching a TalkTalk MX server. Probably the reason for the bounceback error being the receipt of the 503 bad sequence of commands.

Where are you seeing this?  Why would Ionos not be using the published MX record for dsl.pipex.com?  Are you suspecting they are using an out of date cached DNS lookup?

 

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Message 99 of 117

Hi delwynh

 

Just repost but avoid re-editing immediately after posting. The Comment Spam filter does seem to trap some posts that are rapidly edited and reposted.

 

I did see your original post though. I agreed that the spam blacklisting may result in blocking but didn't explain the class of bounceback error message.

 

The Pipex MX lookup does now link to the TalkTalk MX servers. An essential part of the migration to the TalkTalk Mail platform.

 

The Ionos lookup appears to still link first to the Tiscali MX servers before reaching a TalkTalk MX server. Probably the reason for the bounceback error being the receipt of the 503 bad sequence of commands.

GondolaVolunteer 2017-2021

 Like below to appreciate my help . . . Best answer is + Accept as Solution

Message 100 of 117

Hi @Ady-TalkTalk 

 

I just posted a reply with some more information relevant to this problem but it has been marked as spam and removed.  Could it be reinstated please.

 

Thanks

 

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