Yahoo Mail Is The Worst
oneshotblog.com
oneshotblog.com
I suspect the problem is that the IP in question has been used in the past for nefarious purposes. The whole "It's a new server" argument is moot if the IP address it lives on had been used in the past (and it certainly has).
Get right with RFC Jesus, make sure your DNS resolves both ways, get your SPF records right, and if that still doesn't do it, setup DKIM. If that still doesn't allow mail to go through to Yahoo addresses unimpeded, you'll have to contact them.
The idea is that spammers don't use real mail queues and thus, if you send a temporary error, genuine clients will requeue the message, whereas spammers will just drop it.
Over time, this assertion has become false and now it's just annoying.
Over time, this assertion has become false and now it's just annoying.
Do you have some evidence for this claim?
Greylisting heavily reduced the amount of spam I received when I started using greylisting years ago.
I still see large amounts of spam rejected, so I'd like to hear more about how it doesn't work any more - it seems to reduce the spam-level significantly for me.
I don't mind the blocking, I recognize that as a legit way of controlling access, but what is really frustrating is that the hotmail folks assume that I don't know anything about email and that they can't even acknowledge that they have a certain IP blocked. If they could just say "Yes, we've blocked that, and there's nothing you can do or say to get us to unblock it", then we could move on; but when it looks like no one at hotmail knows what's going on, everyone continuously believes that if they just say the magic words or contact the right person, it can all be cleared up.
The solution that I came to in the past to overcome this, working for a large online dating site, was to build a mail relay system that would monitor the response ratio on each IP, and if it dropped below a certain percentage to switch it off onto another. Worked fairly well, only downside is having to manage a lot of IP addresses on your mailer boxes.
I also remember this happening with emailing addresses on the entire AT&T ISP. That effected about 40 shared servers (around 16000 hosting accounts, each with unlimited email). So yeah. Bad news.
We have a few hundred (mostly small) hosting providers running our software which includes a mail processing stack, and quite frequently they ask about stuff like this (and yes, Yahoo comes up more than GMail, but about the same as Hotmail). And, there is very often anger involved, just as in this case. But, the fact is...if you follow RFCs strictly (Zed has written his own newfangled mail server in Python; I suspect he's made some mistakes, as the mail RFCs are notoriously difficult to get right, though the MTA isn't necessarily dealing with all of the messiness of the protocols), have DNS that resolves in both directions, and have accurate SPF records, delivering to Yahoo will work reliably and fast.
We've occasionally gotten comments that DKIM is necessary to deliver to Yahoo, but whenever I hear it, I'm surprised to hear that a major provider has finally started actually blocking on DKIM. So, I go check. I always find that no, DKIM is still not required to deliver to Yahoo. It probably helps, though.
I'm not saying Yahoo doesn't have an itchy trigger finger on the blacklisting process. Maybe they do. They certainly aren't as good as Google at non-obtrusively, but effectively, blocking spam, but very few providers are.