SMC Policy Violation detected

[Postmark]

Recently, emails from our server  to @ntlworld.com addresseses are being blocked and the NDR from Virgin Media states "... Temporary SMC Policy Violation detected ..."

I've posted a sample below.

These emails are all messages to confirmed opt-in subscribers of email discussion-lists hosted on our server. We do not send spam and we have various filters in place to block spam from reaching these lists. We publish SPF and DMARC records and DKIM sign our outgoing mail.

Cisco reports our IP as having a good email reputation with zero spam and not listed on any legitimate blacklists.

It's not clear what "SMC Policy Violation" means, but any assistance in getting this block removed would be greatly appreciated.

Thanks.

Nov  6 21:17:13 lhr postfix/smtp[27647]: 40BCA25A79: to=<REDACTED@ntlworld.com>, relay=mx.tb.ukmail.iss.as9143.net[212.54.56.11]:25, delay=1025, delays=1024/0.02/0.19/0.61, dsn=4.2.0, status=deferred (host mx.tb.ukmail.iss.as9143.net[212.54.56.11] said: 421 4.2.0 MXIN618 Temporary SMC Policy Violation detected, retry later ;id=jT3pmUDGknQyPjT3pmYK4X;sid=jT3pmUDGknQyP;mta=mx7.tb;dt=2021-11-06T22:17:13+01:00;ipsrc=178.62.98.103; (in reply to end of DATA command))

[John_GS]

Hi @Postmark

Thanks for posting and welcome to the community.

Sorry for the confusion here.

Can you send me a PM with the email address in question, your full name and the account it belongs too. The full version of the email including the errors and the header.

I'll forward this on to the relevant team.

Best,

[John_GS · Accepted solution]

Hi @Postmark

Glad to hear it seems sorted. If it happens again do let me know 🙂

Best,