So we have hundreds of shared and dedicated cPanel servers that use the
same domain for the base hostname i.e. server.validns.com,
server2.validns.com etc.

We started to get complaints from users across multiple servers that yahoo
mail was being rejected with:

SMTP error from remote mail server after end of data: 554 Message not
allowed - [PH01] Email not accepted for policy reasons. Please visit
http://postmaster.yahoo.com/errors/postmaster-27.html [120]

This is happening across many servers on different IPs regardless of the
sending domain, dkim/spf etc. It's basically happening to anyone sending
mail to @yahoo.com on any server that is using the validns.com. We have
multiple other servers on different base hostnames on the same IP block
that don't seem to be affected.

So I did some looking in to this and eventually I found a complaint about a
phishing attempt on our hostname coming from serverX.validns.com. A clients
site got hacked and phishing scripts uploaded to it and they were being
called using the server hostname i.e. serverX.validns.com/~cpaneluser/hack
-- this somehow led to the entire validns.com being listed on SURBL multi.
I have no idea why they listed the entire domain VS the full hostname the
source was coming from I.e. instead of listing serverX.validns.com they
listed validns.com.  Fast forward, I cleaned up the phishing and submitted
a removal request to SURBL mutli and the domain was delisted over 2 days
ago and shows good status in their lookup. Ever since Yahoo seems to have
not dropped the listing or whatever they are using internally that is
causing them to reject all messages from any server using this hostname.

Is it possible that yahoo.com picked up on the SURBL listing and are
blocking our entire hostname based on it? I was hoping if so they'd drop it
by now seeing as the listing was removed over 2 days ago, but so far no
such luck. Or is it possible that our validns.com could be listed in some
other URBL that yahoo could be picking up on? So far I've got it off SURBL
multi, checked it on spamhaus DBL and uribl.com and it's not listed on
either of those. There may be others I'm not aware of.

Right now we have hundreds of servers and thousands of users on them that
are unable to mail to yahoo.com and it's causing a huge support mess. It
almost seems impossible to get hold of anyone that can actually help with
the problem at yahoo, I've send emails and forms, everything I can find but
no response back yet.

If whatever block yahoo has on our hostname continues I don't know what
else to do if I can't get a hold of them short of changing the hostnames
(which would be a huge disaster) or trying to find a way to configure exim
to route mail destined to yahoo.com through another mail server (I'd have
to setup one on a different hostname and allow relaying through it) then
configure all the servers to relay yahoo through it. I'm sure it'd work but
it's also quite a bit of work as well.

Has anyone ever dealt with a problem like this? I've been in hosting since
'96 and I can't recall a case where I've ever seen a main hostname get
listed like this while the source of the problem was on a sub-domain.

Thanks!

James
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