nanog mailing list archives
Re: messagelabs.com contact - SMTP-side domaincheck checks IPv4 only, rejects domains with first MX on IPv6
From: Matt Sergeant <msergeant () messagelabs com>
Date: Sun, 05 Jun 2011 18:07:34 -0400
I'll get someone to contact Ford and see what they are running. From google it looks like Exchange. Is this a known bug with Exchange? If so I think there's bigger problems than messagelabs :)
Jeroen Massar wrote:
As the subject states, MAILER-DAEMON () messagelabs com: <....@ford.com>: Connected to 136.1.7.8 but sender was rejected. Remote host said: 501 Sender domain must exist As it obviously checks only the first MX record if there are A records, and if there are none it rejects it. This while there are AAAA records on the first MX, and even A records on the remaining MXs. Thus a proper fix would already be to check the other MXs and of course to check for AAAA too ;) And that affects all customers at messagelabs, thus if somebody can pass that along to them to fix it, that would be great ;) Oh and of course the check is also there for postmaster@ thus no way to tell them through that route. Greets, Jeroen ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email ______________________________________________________________________
______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System.For more information please visit http://www.messagelabs.com/email ______________________________________________________________________
Current thread:
- messagelabs.com contact - SMTP-side domaincheck checks IPv4 only, rejects domains with first MX on IPv6 Jeroen Massar (Jun 05)
- Re: messagelabs.com contact - SMTP-side domaincheck checks IPv4 only, rejects domains with first MX on IPv6 Matt Sergeant (Jun 05)