Problems sending mail to yahoo?

Raymond L. Corbin rcorbin at
Thu Apr 10 19:52:39 UTC 2008

Yeah, but without them saying which IP's are causing the problems you can't really tell which servers in a datacenter are forwarding their spam/abusing Yahoo. Once the /24 block is in place then they claim to have no way of knowing who actually caused the block on the /24. The feedback loop would help depending on your network size. When you have a few hundred thousand clients, and those clients have clients, and they even have client, it simply floods your abuse desk with complaints from Yahoo when it is obviously forwarded spam. So it's more of pick your poison deal with customer complaints about not being able to send to yahoo for a few days or get your abuse desk flooded with complaints which hinders solving actual issues like compromised accounts.


-----Original Message-----
From: Chris Stone [mailto:cstone at]
Sent: Thursday, April 10, 2008 3:33 PM
To: Raymond L. Corbin
Cc: nanog at
Subject: Re: Problems sending mail to yahoo?

Hash: SHA512

Raymond L. Corbin wrote:
> Hello,
> I have had to tell some dedicated server clients that they will need to disable their forwards to Yahoo or add something like postini for those accounts that forward to Yahoo...It generally works...however Yahoo! for the past three months is now blocking entire /24's if a few IP's get complaints. They have the feedback loops however when you have a network with 175,000 IP addresses and you sign up for a feedback loop for them all they tend to flood your abuse desk with false positives, or forwarded spam. They also don't keep track of which IP's are getting the complaints for you to investigate after the block on the /24 so asking them won't help :(. This potentially means one customer could easily effect the other customer. They offer whitelisting, but this won't get you passed their blocks on the entire /24. They apparently will eventually accept the message because they aren't necessarily 'blocked' but they are 'depriortized' meaning they don't believe your IP is importan
t enough to deliver the message at that time, so they want you to keep trying and when their servers are not 'busy' or 'over loaded' they will accept the message. (Paraphrased from conversations with their 'Bulk Mail Advocacies and Anti-Abuse manager.)

I've had to tell some of our customers the same and that if they wanted to
continue the forwarding to their accounts, they'd need to add spam
filtering to their accounts here so that the crap is not forwarded,
resulting in the email delays for all customers. Works for some and
generated more revenue.... ;-)


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