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False rejection of valid sender domain

Superuser
Superuser
Posts: 9,926
Thanks: 1,265
Fixes: 71
Registered: ‎06-04-2007

Re: False rejection of valid sender domain


@SteveA wrote:
So if the include _spf-internal2.madasafish.com record is wrong then hopefully PN can fix it and that would fix the issues.

That spf include isn't wrong. the relay.{force9,free-online,plus}.net family are mail submission agents we communicate with. They pass mail onto a cluster of avasoutxx MTA servers for external transfer. It is the latter that need SPF text entries and the the first two ip4: ranges specified cover these.

The invalid domain error comes from the relays because that is where (in this instance) the mail from (sender)  address is being checked. The presence or absence of SPF records has no bearing on this. It's a DNS lookup problem - relay.plus.net has checked DNS and been given a dud answer.

Earlier in this thread (Message #47) a staff member advised your issue had been included in the problem investigation notes.

David
newlands
Hooked
Posts: 6
Registered: ‎10-02-2017

Re: False rejection of valid sender domain

I am still getting "Diagnostic-Code: smtp; 550 #5.1.8 Domain of sender address <a@b.c> does not exist".

Yesterday (2018-11-27) one of my machines sent an email from a@b.c to one of my plusnet email addresses, let's call it x@z.plus.com, at 19:01:56.
About 15 minutes later at 19:16:47, the same machine sent an identical email from a@b.c to x@z.plus.com.

The first one got through:
Delivery-date: Tue, 27 Nov 2018 19:02:00 +0000
Received: from [212.159.8.109] (helo=avasin19.plus.net)
      by inmx07.plus.net with esmtp (PlusNet MXCore v2.00) id 1gRicS-0004fH-0p

The second one got "550 #5.1.8 Domain of sender address <a@b.c> does not exist", even though that Domain was accepted 15 minutes earlier.

Then, of course, the failing email was returned to the sender (a@b.c) with: "A message that you sent could not be delivered to one or more of its recipients."
The domain b.c is hosted external to plusnet and managed by me and is set up to forward mail for a@b.c to x@z.plus.com and this got through!
Delivery-date: Tue, 27 Nov 2018 19:17:03 +0000
Received: from [212.159.9.108] (helo=avasin20.plus.net)
      by inmx06.plus.net with esmtp (PlusNet MXCore v2.00) id 1gRir1-0004YI-DQ

Townman keeps asking what the inbound email server was when it fails but I do not know how to find that.
If it would help to get this problem fixed I will send the pair of emails, the one that failed and the one that succeeded, to anyone in the Plusnet Help Team.

Superuser
Superuser
Posts: 13,047
Thanks: 4,337
Fixes: 26
Registered: ‎22-08-2007

Re: False rejection of valid sender domain

The headers of the non-delivery report ought to identify the Plusnet receiving server.

newlands
Hooked
Posts: 6
Registered: ‎10-02-2017

Re: False rejection of valid sender domain

Townman

 

Is it the lines that say:

Status: 5.0.0
Remote-MTA: dns; mx.avasin.plus.net
Diagnostic-Code: smtp; 550 #5.1.8 Domain of sender address <a@b.c> does not exist

 

If that is not the answer you're looking for, I need more help.  Can I send it to you, please?

Community Veteran
Posts: 1,671
Thanks: 81
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Registered: ‎17-06-2007

Re: False rejection of valid sender domain

This now seems to be happening a lot more frequently than it was before. I'm now getting it on average more than once a day now.

 

How hard can it be to fix?

 

 

Superuser
Superuser
Posts: 13,047
Thanks: 4,337
Fixes: 26
Registered: ‎22-08-2007

Re: False rejection of valid sender domain

… as hard as finding a discernible pattern!!

This is not a "solid" issue, it is intermittent and therefore has something to do with a specific route or characteristic of the failing occasions.  What appears to the outside world as a "single" service or resource (SMTP or DNS service) is not so simple behind the scenes.  Everything has at least two externally visible IP addresses and each IP address has an array of service instances behind it.  The issue is therefore hard to locate.

As requested previously, the identification of the mail gateway involved in reports might be of some help.

Community Veteran
Posts: 1,671
Thanks: 81
Fixes: 2
Registered: ‎17-06-2007

Re: False rejection of valid sender domain

From today

 

Dec  7 07:16:56 Debussy postfix/smtp[20085]: A52AD640429: to=<submit.iwQPrtiU0m87m2AR@spam.spamcop.net>, relay=relay.plus.net[212.159.9.107]:25, delay=16, delays=0.17/0.01/1.1/15, dsn=5.0.0, status=bounced (host relay.plus.net[212.159.9.107] said: 550 <xxxx@xxx.org.uk> sender rejected - invalid domain (no MX or A record) (in reply to MAIL FROM command))
Dec  7 18:00:31 Debussy postfix/smtp[16740]: 85F86640429: to=<submit.iwQPrtiU0m87m2AR@spam.spamcop.net>, relay=relay.plus.net[212.159.9.107]:25, delay=15, delays=0.17/0.01/1.2/13, dsn=5.0.0, status=bounced (host relay.plus.net[212.159.9.107] said: 550 <xxxx@xxx.org.uk> sender rejected - invalid domain (no MX or A record) (in reply to MAIL FROM command))
Dec  7 18:03:24 Debussy postfix/smtp[17610]: D278A640429: to=<submit.iwQPrtiU0m87m2AR@spam.spamcop.net>, relay=relay.plus.net[212.159.8.107]:25, delay=1.5, delays=0.09/0.01/1.1/0.25, dsn=2.0.0, status=sent (250 VKTDgwgSpx6b6VKTEgL9tC mail accepted for delivery)

So two fails on 212.159.9.107 several hours apart

then a successful send on 212.159.8.107 3 minutes after the fail.

 

Superuser
Superuser
Posts: 9,926
Thanks: 1,265
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Registered: ‎06-04-2007

Re: False rejection of valid sender domain

@SteveA

When you see

sender rejected - invalid domain

in your server logs, is this always (or generally) associated with IP 212.159.9.107, whereas 212.159.8.107 normally works?

For diagnostic purposes you could try replacing relay.plus.net by 212.159.8.107 in the Postfix configuration to see if this reduces failure instances.

David
Community Veteran
Posts: 1,671
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Registered: ‎17-06-2007

Re: False rejection of valid sender domain

Looking back at the logs yes it looks like fails always come from 212.159.9.107

 

Postfix updated to use .8.107 rather than the host name.

 

Will see how it goes.

Community Veteran
Posts: 1,671
Thanks: 81
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Registered: ‎17-06-2007

Re: False rejection of valid sender domain

and one this evening bouncing an email over to my brother (also a PN use who uses an external domain)

 

  host mx.avasin.plus.net [212.159.9.200]

 

newlands
Hooked
Posts: 6
Registered: ‎10-02-2017

Re: False rejection of valid sender domain

Looking back at the logs for my fails over the last month, most of them have also come from 212.159.9.200

I can no longer live with these random failures with plusnet's mail servers for a problem that has been around for ages and does not appear to be getting any serious attention from plusnet


So I have given up with plusnet's mail servers and moved to tsohost for mail hosting and have had no problems at all - fantastic service!

drj
Aspiring Pro
Posts: 1,106
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Registered: ‎30-03-2011

Re: False rejection of valid sender domain

Bear with me - I'm very non-technical!

 

I seem to be experiencing exactly the same issue as the OP - I'm getting this sort of message on two of my domain names - the emails usually go once resent but it shouldn't be happening?

 

Mail Delivery Subsystem <mailer-daemon@googlemail.com>

Thu, 6 Dec, 14:05 (3 days ago)
   
to me

 

 
 
 
 
Error Icon

Message not delivered

You're sending this from a different address or alias using the 'Send mail as' feature. The settings for your 'Send mail as' account are misconfigured or out of date. Check those settings and try resending.
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The response from the remote server was:

550 <[me]@[my domain name]> sender rejected - invalid domain (no MX or A record)

Plusnet Help Team
Plusnet Help Team
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Registered: ‎11-01-2018

Re: False rejection of valid sender domain

 

Thanks for that additional info, @SteveA - I've passed it across to our network team.

 

Best wishes

 

Dave

If this post resolved your issue please click the 'This fixed my problem' button
 Dave G
 Plusnet Help Team
Community Veteran
Posts: 1,671
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Registered: ‎17-06-2007

Re: False rejection of valid sender domain

I've had no failures at my end since I moved away from relay.plus.net to the fixed IP - of course it now means that I'm relying on one specific server being available......

Silanthril
Newbie
Posts: 4
Registered: Monday

Re: False rejection of valid sender domain

I am having the exact same problem. Some valid emails are being rejected (my bank, my work and my estate agent) and the headers are reporting the sender does not exist.

 

PN support are aware of my issue, but seem to be doing nothing as I flagged it on 16th November and they only respond once a week if at all.

 

It does seem to be intermittent - same account can send emails a minute later and it will get through.

 

Thoroughly frustrated, so any advice gratefully received.

 

Thanks