Long Delay receiving emails forwarded from 123.reg

[agpvm]

(See also thread here: Long-Delay-receiving-emails - 4090443 )

I too am getting long delays, and even the occasional total failure with emails being forwarded from 123-reg to Virgin Media.

It appears that the reason is that Virgin Media have set a Limit of just 20 for the number of simultaneous connections that 123 can have to Virgin Media servers when sending/forwarding emails to them.  123 are very frequently exceeding this limit, causing their connections to be rejected.  Our messages then get delayed and  tried again later, and each time it fails the delay gets even longer.  So often messages aren't getting through for many hours.

Unfortunately Virgin Media are blaming 123 and 123 are blaming Virgin Media, with neither company passing the information on to the people who could actually resolve this.

Virgin Media's Limit of 20 is the default value - but they could increase it.  123 are exceeding the default value but could set their limit to 20 when sending to Virgin Media, or could just not back off for so long.

Here's part of an example of a rejection message:

A message that you sent has not yet been delivered to one or more of its
recipients after more than 6 hours on the queue on smtp12.mailcore.me.
...
The address to which the message has not yet been delivered is:
...
host mx.tb.ukmail.iss.as9143.net [212.54.56.11]
Delay reason: SMTP error from remote mail server after initial connection:
421 mx1.tb.ukmail.iss.as9143.net mx1.tb.ukmail.iss.as9143.net
logid=SMTPRC 421 MXIN106 Parallel SessionLimit of 20 for your 94.136.40.149 exceeded. Retry later.
;id=PdHgiN4hD3aVY;sid=PdHgiN4hD3aVY;mta=mx1.tb;d=20191030;t=030028[CET];ipsrc=94.136.40.149;

Alan

[agpvm]

I too am getting long delays, and even the occasional total failure with emails being forwarded from 123-reg to Virgin Media.

It appears that the reason is that Virgin Media have set a Limit of just 20 for the number of simultaneous connections that 123 can have to Virgin Media servers when sending/forwarding emails to them.  123 are very frequently exceeding this limit, causing their connections to be rejected.  Our messages then get delayed and  tried again later, and each time it fails the delay gets even longer.  So often messages aren't getting through for many hours.

Unfortunately Virgin Media are blaming 123 and 123 are blaming Virgin Media, with neither company passing the information on to the people who could actually resolve this.

Virgin Media's Limit of 20 is the default value - but they could increase it.  123 are exceeding the default value but could set their limit to 20 when sending to Virgin Media, or could just not back off for so long.

Here's part of an example of a rejection message:

A message that you sent has not yet been delivered to one or more of its
recipients after more than 6 hours on the queue on smtp12.mailcore.me.
...
The address to which the message has not yet been delivered is:
...
host mx.tb.ukmail.iss.as9143.net [212.54.56.11]
Delay reason: SMTP error from remote mail server after initial connection:
421 mx1.tb.ukmail.iss.as9143.net mx1.tb.ukmail.iss.as9143.net
logid=SMTPRC 421 MXIN106 Parallel SessionLimit of 20 for your 94.136.40.149 exceeded. Retry later.
;id=PdHgiN4hD3aVY;sid=PdHgiN4hD3aVY;mta=mx1.tb;d=20191030;t=030028[CET];ipsrc=94.136.40.149;

Alan

[Lucy_B]

Hi, 

Thanks for your patience whilst this was investigated. 

We've made some changes which should stop these errors appearing when forwarding mail, please let us know if you are still experiencing any issues. 

Our team have also investigated some of the headers provided and have recommended ensuring that you have valid DMARC & SPF set up if you’re using your own domain.

Thanks

Lucy_B

[cunnith]

>Our team have also investigated some of the headers provided and have recommended ensuring that you have valid DMARC & SPF set up if you’re using your own domain.

Can someone please give detailed instructions for how we do that in the case of forwarding from 123-reg.

[ravenstar68]

@Lucy_B 

Please stop and think for a moment.  These users are having mail sent to their own email domains - and then forwarded on to their Virgin Media mailboxes.

SPF, DMARC, and DKIM, are used by the ORGINAL SENDING DOMAIN - to prove that the mails are authentic.

There is nothing that your customers can do to affect this.  In fact because they are using forwarding SPF WILL FAIL and unless the senders use DKIM as well so will DMARC.

Tim

[emailwoes]

I agree with Tim, plus I'm still getting delayed email (one sent to me 20mins ago has not appeared)

[Lucy_B]

Hi Tim, 

Thanks for the correction; I only mentioned this as some additional guidance, as after investigating the headers provided our internet security team noticed that some of the domains in questions did not have this in place. 

Thanks

Lucy_B

[agpvm]

Like emailwoes, I am still getting delays on emails. This afternoon I've had 1hr,  30min, and 22min delays - with some emails arriving promptly.

My impression so far is that the VM changes have made some improvement, but that a greater tweak is required.

I am however pleased that VM are actively investigating this, and hope that a further step will happen.

Alan

[Lucy_B]

Hi All, 

I just wanted to give you a quick update; Some more adjustment have been made, and we are actively monitoring the mailflow throughout and will be making adjustment if any issues are noticed. 

Could you please monitor this over the next 48 hours and let us know if the issue persists?

Thanks

Lucy_B

[3_g]

@Lucy_B - sorry to say the delays are still happening as at 16:30 GMT on Tuesday 17 December 2019!

For some of the email addresses I used with my domain name hosted by 123-Reg, I have them going to a Gmail account and my Blueyonder email address.  An email received at Gmail was delivered to VM 22 minutes later, another email sent a few minutes previously still has not come through to VM (yes I've checked junk!)

If the mail team require any logs or headers I am happy to be DM'd and provide these.

Ewan

[agpvm]

@Lucy_B

Same here- 20 to 30 minute delays seem typical today.
(I'm also duplicating emails to VM and gmail so that I can monitor the delays)

Just a suggestion:- tuning too close to the current traffic rates mightn't be good enough as many users are currently using work-arounds to avoid the issue (such as forwarding from 123 to gmail and then to VM).  We will all wish to go back to forwarding direct to VM from 123 when possible thus increasing the traffic.

Alan

[cunnith]

A test email I sent at 16:23 today only arrived at 18:10 so the issue is certainly not resolved.