From: Brion on
All of a sudden, late last week, none of our users can send email to Yahoo.
There are a bunch of messages queued with the error "421 4.4.2 Connection
dropped." Delivery to all other domains is fine. I have checked and we are
not on any blacklists. We are running Exchange 2007. I have contacted
Yahoo about this, and they did get back to me, but via email, and the
conversation has been going in slow motion for a few days now with no
resolution.

Has anybody else seen these 421 4.4.2 errors when delivering to yahoo? How
did you get around it?

Thanks!

From: John Oliver, Jr. [MVP] on
Could be a few reasons, do you have a SPF Record? Do you have a Reverse DNS
Pointer record? A copy of the exact NDR message that is fired back when the
message times out would also be helpful.

--
John Oliver, Jr
MCSE, MCT, CCNA
Exchange MVP 2010
Microsoft Certified Partner


"Brion" <blah(a)blah.com> wrote in message
news:#5TWEDs9KHA.5808(a)TK2MSFTNGP02.phx.gbl...
> All of a sudden, late last week, none of our users can send email to
> Yahoo. There are a bunch of messages queued with the error "421 4.4.2
> Connection dropped." Delivery to all other domains is fine. I have
> checked and we are not on any blacklists. We are running Exchange 2007.
> I have contacted Yahoo about this, and they did get back to me, but via
> email, and the conversation has been going in slow motion for a few days
> now with no resolution.
>
> Has anybody else seen these 421 4.4.2 errors when delivering to yahoo?
> How did you get around it?
>
> Thanks!