Troubleshooting Yahoo delivery

Last week Jon left a comment on my post Following the Script. He gives a familiar story about how he’s having problems contacting Yahoo.

It’s funny, I found this thread by searching for alternate means to contact Yahoo FBL. This is because I desperately need to communicate with them and their ‘normal channel’ has been literaly as effective as a shout down a wishing well. […] I’ve signed up for all the various FBL’s with the major providers and we’re tracking reputation nicely as we warm up the sending IP’s with about 75K mails a day over the last month. Yahoo! of course is 35%+ of that mail. However they’re blocking the heck out of my mails from time to time. For the last few days one of my sending IP’s is almost completely blocked while the other three are not. This causes horrible delays. I think that the longer expected mail is delayed the more likelihood it has of being marked as spam or ignored.

There are a couple suggestions I have for people in Jon’s position.

1. IP address warmup can take from 6 – 8 weeks, particularly at Yahoo. Given the current situation with bots, IP addresses that have never sent mail to the major ISPs don’t start out with a neutral reptuation, they actually start out with a negative reputation. In 99 out of 100 times, the IP address that has never sent mail is an infected machine sending spam. Real IP addresses will send mail consistently over the long term, but it can take time to establish a reputation with the ISP.  While it’s not really what anyone wants to hear, senders need to be patient during the warm up process. If it’s possible, starting with low sending volumes (under 5000 emails per ISP per day) and increasing the amount slowly seems to help minimize the temporary failures.
2. Confirmation emails can be problematic, depending on how the email addresses are being collected. If there are too many fake or incorrect subscriptions coming in through a subscription form,  then you will see excessive complaints that may damage the reputation of the sending IP.  Likewise, if the subscription page does not correctly set the expectations of the recipient, the sender may see a high number of complaints. Subscription problems can be managed if you understand what the complaints are about, but you need to do some research to determine that.
3. Confirm that your technology is sending mail in a way that the recipient ISP likes. For Yahoo, this means limiting the number of connections and the number of emails per connection. One of my clients was having difficulty with Yahoo delivery and we resolved the problem by throttling their server to 2 connections at a time and 4 emails per connection. Yahoo will throttle senders that try more than 5 emails in a single connection, and this is simple to fix.
4. Read the bounce messages. Yahoo has rolled out an extensive Postmaster Site in the last few months, which includes a lot of information about bounces and improving delivery. If none of the FAQ questions answer your question, there is also the Yahoo Delivery Support Form.

One important thing to remember, when reaching out to any ISP for help with a delivery issue is that the contact is extremely unlikely to result in the ISP letting all your mail in. As I tell my clients all the time, there is no place in the spam filtering for “this is a good guy” or “this persons mail should be exempt from all our checks.” Senders can troubleshoot 95% of issues themselves. However, in those relatively rare cases where the sender can’t fix the issue, generally the only the the ISPs can do is answer questions. They can’t provide solutions, just more places to look for troubleshooting.