Emails being throttled/blocked when contacting Virgin Media contacts

[MJRMarques]

Hello, community.

I hope all is good.

I work for an ESP and I have noticed an increase in the throttling of the emails one of our clients sends to virginmedia.com/ntlworld.com/blueyonder.co.uk/virgin.net.

The error I get is: 

smtp;421 4.1.1 MXIN503 Hourly ratelimit for your IP exceeded ;id=zDa7mBqYaONfozDa7m67Ys;sid=zDa7mBqYaONfo;mta=mx2.tb;d=20211220;t=085939[CET];ipsrc=[ip address];

This was not happening previously and we had no issues with the delivery of the emails. Does anyone know if anything has changed on the mailservers from Virginmedia that is causing this issue?

I have also contacted the postmaster email, however, the reply I received has no indication of what to do, any causes, etc. It's just an automatic reply from the system.

Thank you in advance for your help.

Regards,

MJRMaqrques

[coenoby · Accepted solution]

---

@MJRMarques wrote:: 

smtp;421 4.1.1 MXIN503 Hourly ratelimit for your IP exceeded ;id=zDa7mBqYaONfozDa7m67Ys;sid=zDa7mBqYaONfo;mta=mx2.tb;d=20211220;t=085939[CET];ipsrc=[ip address];

This was not happening previously and we had no issues with the delivery of the emails. Does anyone know if anything has changed on the mailservers from Virginmedia that is causing this issue?

---

That is an error message that gets reported here from time to time so I don't think it's necessarily the result of any change at Virgin Media's end.

VM rate limit because they think that the mail looks suspiciously like spam. It could be because your client is sending too many emails per hour as the error message suggests or it could be that the DMARC. DKIM, and SPF settings being used are a cause for concern. It could even be that your mail server is misconfigured so that the DNS lookup and reverse DNS look up point to the wrong place or don't point to a FQDN. VM do seem to be strict with that.

It's a pity that you have had no specific response from the Postmaster email. The Forum Team (VM employees who support this forum) may be able to raise this with the Postmaster team.

I have escalated your post to the Forum Team and hopefully one of them should contact you via the forum.

Coenoby

[Lee_R]

Hi MJRMarques thanks for posting and welcome to our community.

I am sorry to hear a client of yours is having issues with our emails.  I am going to send you a private message to see what we can do to help.

Regards

Lee_R

[MJRMarques]

Hello Coenoby

Thanks for your reply and I am sorry for not being able to reply earlier.

I have limited the number of emails sent per hour to 3000 (considering all domains) and I still get the same issue (on a lower scale). This also causes the send time to be lower and emails to be delivered at a lower speed. I had to compromise. I did not mention it before, but this. is a migration from an old to a new IP range. 

I have contacted the postmaster once more, unsuccessfully. Is there any other mailbox we can use to communicate with Virgin Media? I have also tried to contact as9143.net and Ziggo, however, in one case I got no reply and on the other, the email address bounced.

kind regards,

M. Marques