Re: Exchange mailing to A records intermittently instead of MX records ???

Which KB article?

"Denis" <denis@xxxxxxxxxx> wrote in message
news:eAmK3zvhFHA.576@xxxxxxxxxxxxxxxxxxxxxxx
> We are experiencing very bizarre stuff on our exchange servers when
> mailing
> to external domains.
>
> SMTP delivery is working fine and then all of a sudden we start getting
> failure reports back.
> We've been digging around and tracking, and we find that all of a sudden
> the
> SMTP virtual server is trying to deliver to the IP address of the A record
> for the domain, instead of to the IP address of the MX record. As in most
> cases this is the web server, we get a response back indicating that the
> server cannot relay for that domain, which is normal.
>
> My question is: why does the SMTP connector decide to send to the A record
> all of a sudden, instead of to the MX record ???
> Can we tell exchange to only attempt mailing to MX records ?
>
> I looked into the DNS caches and the information is correct.
> I ran DNSDIAG on our Exchange servers, against the various destinations
> and
> on the various virtual SMTP servers, and they all come back with the
> appropriate MX information. I don't know where to look anymore.
>
> BTW: after awhile it will revert sending to the MX records, as if nothing
> happened ...
>
> Our Exchange servers are multihomed systems. There is a single SMTP
> Virtual
> Server (VS) connector for each NIC. The SMTP VS on the external connector
> looks at our internal DNS servers, while the SMTP VS on the internal
> connectors looks to external DNS servers. (Setup according to one of MS's
> KB
> articles).
>
> Any ideas ?
>
> Thanks.
> Denis.
>
>
>


.

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