Sorry for the cross post to 2 different areas but we're in need of some opinions quickly
We seem to be having multiple mail servers on multiple networks having issues sending to yahoo servers for going on 36 hours now
these are a variety of server types on a variety of networks
telnet on port 25 is usually getting this
451 Message temporarily deferred - 4.16.50
keep in mind that some of our servers are having no issues sending mail
Do you have a common client on all of those servers that may have been sending spam? This could have gotten your IPs blacklisted. I would recommend calling or contacting the Yahoo! Postmaster if you would like to get this straight in as little time as possible - they are the only ones who can give you definitive advice.
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Here's what we think is happening so far - comments are appreciated - by the way - we have comfirmed with a few dozen mail providers so far that this is happening
Yahoo is grey listing but instead of running a centralized GL database each of their servers has it’s own
Same problem here. Have written emails to the postmaster and no luck. If I hear back I will quickly post a response. This has happened before about 8 months ago. I guess if you're a yahoo customer, you get what you pay for....
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I cannot confirm this, but I have problems with yahoo servers too and based on my logs Yahoo does some sort of selective greylisting. If your server is misconfigured to provide a HELO greeting that yahoo thinks is invalid, then you get greylisted.
I base this behaviour based on this log message:
I think they greylist by IP only, which is why any connections to the servers thereafter (by telnet or whatever) will be rejected for a period of time.
Same thing here...
No yahoo users seem to be receiving mail from our servers, we even have a postcard service that is having trouble with yahoo not showing the postcards their users receive.
Looking up logs and such it seems Yahoo mail servers are listening to our servers, and even receiving the mail... it's just that it is choosing not to show it to users, not even as spam. We receive no failed messages from yahoo either.
This, has been going on since last friday... it seems Yahoo is being too aggressive by what I see, especially reading this thread where lots of us are having bassically the same issues these last days.
Please keep us updated on anything you all go through with this issue.
Yahoo seems to be rate limiting, we are seeing the same thing as user pointed it out, and then we checked all servers were having this. It is not spam related at all they are putting a limit on messages per hour from each IP as far as I can tell.
Of note is that premium yahoo! accounts and partner network yahoo accounts (like Verizon DSL), work isntantly and do not have this. It seems to only be the free accounts with this limit in place on the sending mail servers.
i doubt rate limiting would account for not being able to telnet to port 25 from various locations
i.e. dnsreport.com, a desktop or router
i've dealt with our issue by manually making entries to 1 server on their network where we are pointing all mail and have programmed our dns failover to update the record based on the availability of port 25 on that server. If it is not available our record is updated to point to another
I'm still not sure if I'm sold on this greylisting thing. I think this is a bad decision by Yahoo.
I know everyone gets spam. I know everyone complains about the amount of spam that they get. And I suppose the best way to stop spam from coming to your server is to just stop accepting mail. I might try that with our servers. I'll send out a notice, "Due to the amount of spam that users have been complaining about, we are going to stop offering e-mail as a webhosting feature, this will put an end to all of your spam problems once and for all." You think that will go over well with our customers?
We had one server where a lot of users were forwarding mail to yahoo addresses. We had written those clients informing them of this problem and telling them that they were likely not receiving a lot of e-mail. Still users continue to want to forward their mail to yahoo.com (I'm already well aware of the inherent problems with forwarding mail off of the server, but getting the clients to understand this is a different story). Yesterday, I put up blocks that rejected e-mail addresses that forwarded mail to @yahoo.com addresses. The mail queue on this server dropped dramatically. I checked this morning, and mail is still being rejected by Yahoo. I checked and today (11 hours into the day) there were 15 messages sent to @yahoo.com. Of these 15 messages, not a single one was delivered to Yahoo. I could understand this if you were looking at a bulk sending of messages to Yahoo, but 15 messages in 11 hours is not quite what I would consider bulk sending.
I understand the spamming problem, and I understand that Yahoo has a much larger user base. I suspect that they are getting bombarded with complaints regarding the spam. But it seems to me that their solution is to just block all e-mail. At this point, I'm not sure how anybody can feel comfortable using an @yahoo.com e-mail address. Who is to say that you are missing many messages due to this Yahoo greylisting block or whatever it is? If Yahoo continues to use this method, then this will have to start becoming my policy regarding this. If you are using an @yahoo.com e-mail address you are probably losing hundreds of messages. Perhaps a large portion of those messages really are spam, but others could be important e-mails.
I don't know what this issue is related to. The 4.16.50 error has been going on for over a week. It is resulting in a large backlog of our mail queues and causing problems with lost e-mail. Perhaps if users stop using Yahoo for their e-mail, then this tactic will be reviewed by Yahoo.
sounds like you've missed something in your understanding of greylisting, and potentially email..
smtp has some resilience built into the protocol - if it cant connect the first time, it tries again, and again, and again, usually for 3-5 days. this is what greylisting takes advantage of - it says no the first time and stores your mta address - this is because it knows you'll try and redeliver
i know im not missing mails, despite the fact i have a yahoo account. if your mail server cant handle a largish mailqueue, then maybe you've either misconfigured, or underprovisioned your hardware/software..
if i was one of your customers id be more worried with what you were doing than what yahoo are doing
Greylisting isn't a bad thing, in fact it has weeded out 99% of my SPAM.
But the way Yahoo is greylisting is unacceptable in my opinion. I have verified what most people have said and yahoo indeeds rejects you on connection giving a 451 error. It continues to block the connection for well over 24 hours which is the "unacceptable" part I am talking about. I am not really sure what goes on at Yahoo, but most of my mail to yahoo accounts don't arrive until one or two days later.
The author of the original greylisting paper suggested that blocking should be set to only 1 hour. It also recommends that greylisting should be checked with the (ip,mail_from,rcpt_to) triplet and automatic whitelisting should occur when the triplets pass. This is to ensure email/internet usability and to reduce the burden for users that frequently sends mail to the same address.
Based on Yahoo's behavior, it is unlikely that Yahoo has decided to follow the recommendations at all and had their own interpretation of greylisting. They seem to block soley based on IP (bad idea), choosing a exteremly long of a delay time (1 day+ or random??) and not using automatic whitelisting (very bad idea, basically, I get greylisted for nearly every mail I send even if my server has suceeded in sending mail in the past). This implementation will damage innocent ISPs by filling their mail queue and generate lots of unncessary traffic.
Again, I don't know how yahoo works, so don't treat these words as official information.
P.S. I also agree that blocking clients from emailing yahoo addresses is a bad idea.