20% of email doesn't make it to the inbox

Return Path released their global delivery report for the second half of 2009. To put together the report, they look at mail delivery to the Mailbox Monitor accounts at 131 different ISPs for 600,000+ sends. In the US, 20% of the email sent by Mailbox Monitor customers to Return Path seed accounts doesn’t make it to the inbox. In fact, 16% of the email just disappears.
I’ve blogged in the past about previous Return Path deliverability studies. The recommendations and comments in those previous posts still apply. Senders must pay attention to engagement, permission, complaints and other policy issues. But none of those things really explain why email is missing.
Why is so much mail disappearing? It doesn’t match with the philosophy of the ISPs. Most ISPs do their best to deliver email that they accept and I don’t really expect that ISPs are starting to hard block so many Return Path customers in the middle of a send. The real clue came looking at the Yahoo numbers. Yahoo is one of those ISPs that does not delete mail they have accepted, but does slow down senders. Other ISPs are following Yahoo’s lead and using temporary failures as a way to regulate and limit email sent by senders with poor to inadequate reputations. They aren’t blocking the senders outright, but they are issuing lots of 4xx “come back later” messages.
What is supposed to happen when an ISP issues a 4xx message during the SMTP transaction is that email should be queued and retried. Modern bulk MTAs (MessageSystems, Port25, Strongmail) allow senders to fine tune bounce handling, and designate how many times an email is retried, even allowing no retries on a temporary failure.
What if the missing mail is a result of senders aggressively handling 4xx messages? Some of the companies I’ve consulted for delete email addresses from mailing lists after 2 or 3 4xx responses. Other companies only retry for 12 – 24 hours and then the email is treated as hard bounced.
Return Path is reporting this as a delivery failure, and the tone of discussion I’m seeing seems to be blaming ISPs for overly aggressive spamfiltering. I don’t really think it’s entirely an ISP problem, though. I think it is indicative of poor practices on the part of senders. Not just the obvious permission and engagement issues that many senders deal with, but also poor policy on handling bounces. Perhaps the policy is fine, but the implementation doesn’t reflect the stated policy. Maybe they’re relying on defaults from their MTA vendor.
In any case, this is yet another example of how senders are in control of their delivery problems. Better bounce handling for temporary failures would lower the amount of email that never makes it to the ISP. This isn’t sufficient for 100% inbox placement, but if the email is never handed off to the ISP it is impossible for that email to make it to the inbox.

iContact lists compromised
Timeliness of email

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E-Postage Just Won't Die

E-Postage is back! Wired covers a report from New Scientist. Here’s what they have to say: “Yahoo’s researchers want you to voluntarily slap a one-cent stamp on your outgoing e-mails, with proceeds going to charity, in a bid to cut down on spam. Can doing good really do away with spam, which consumes 33 terawatt hours of electricity every year, not to mention way too much of our time?”
Alex Rubin at Return Path says hold up, wait a minute. He writes: “Our contacts at Yahoo! tell us this idea is purely in the research realm, and is not scheduled for development in Yahoo! Mail. In other words: it isn’t even vaporware and isn’t likely to be a part of the Yahoo! mail system anytime soon.” He goes on to say (I’m paraphrasing) that oops, Yahoo didn’t really intend for this research to become public.
So, apparently, there are no plans for Yahoo to roll out E-Postage today, tomorrow or next week. Nothing to see here, beyond a simple web site and some thoughts from a Yahoo researcher. Some individual’s hopeful vision for the future, not a corporate announcement of an upcoming product.
E-Postage has always been a neat idea, I’ve thought. A neat idea beset by insurmountable problems. First, end users don’t want to pay for the email messages they send, they want all you can eat. With years of webmail providers offering free email access, you’ll have a heck of a time convincing somebody’s grandmother that they have to pony up a nickel to be able to email the grandkids.
Then, answer me this: Who’s going to handle the economics on the back-end? And any time you have a computer storing a resource (like, say, account information for that tiny little bit of money you’ll need to be able to send me an email), that information can be hacked, exploited, stolen. You think spammers are actually going to pony up? Why would they? They’ll just hack into millions of exploitable computers, stealing five cents from everyone along the way, and gleefully shoveling millions of spams into millions of inboxes.
This concept of E-Postage, either paying money to send email, or spending “computational power” to send email, has been kicking around for years. Periodically, some researcher comes up with the idea anew, and suggests that we all immediately adopt their sure fire plan to solve the world’s spam problem, immediately, pennies at a time. These ideas never seem to go anywhere. And that will never change until somebody can actually convince most of the world to adopt their proposed scheme. Will it ever happen? Never say never, but I have no plans to rush out and buy e-Stamps any time soon.
— Al Iverson

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Matt Blumberg joins the DMA Board

Matt Blumberg, CEO of ReturnPath, announced on his blog today that he has joined the board of the DMA. The blog post is both an explanation of why he did it and an agenda for what he wants to accomplish.

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Delivery Metrics

Last week ReturnPath published a study that shows 20% of permission based email fails to be delivered to the inbox. For this study, ReturnPath looked at the mail sent by their mailbox monitor customers and counted the number of deliveries to the inbox, the number of deliveries to the bulk folder and the number of emails that were not delivered.
At US ISPs 21% of the permission based emails sent to the ReturnPath probe network did not make it to the inbox. 3% of the emails sent went to the bulk folder and 17% did not make it to the mailbox at all.  MSN/Hotmail and Gmail were the worst ISPs to get mail to. They each failed to deliver more than 20% of the mail that was sent to them. At Canadian ISPs, even less of the mail made it to the inbox, primarily because primus.ca is such a large portion of the Canadian market and they use Postini as a filter. Postini is a quite aggressive filter and takes no feedback from senders.
ReturnPath’s take home message on the survey is that one set of metrics is not enough to effectively evaluate a marketing program. Senders need to know more about their mailings than they can discover from just the bounce rate or the revenue rate or response rate or open rate.
There are a lot of reasons an email doesn’t get to the recipient’s inbox or bulk folder. Mail can be hard blocked at the MTA, and rejected by the ISP outright. Mail can be soft blocked at the MTA and the ISP can slow down sending. Sometimes this is enough to cause the sending MTA to stop attempting to deliver the mail, thus causing mail to not show up. Both of these types of blocks are usually visible when looking at the bounce rate.
Some ISPs accept mail but then fail to deliver it to the recipient. Everything on the sender end says the ISP accepted it for delivery but the ISP just drops it on the floor. This is the type of block that a mailbox monitoring program is best able to identify.
Despite all the discussions of numbers, many marketers are still not measuring the variables in their email campaigns. Ken Magill wrote today about a study released by eROI that indicates more than a third of marketers are not doing any testing on their mailings.
Now, both of these studies are done in an attempt to sell products, however, the numbers discussed should be making smart senders think about what they are measuring in regards to their email campaign, how they are measuring those factors and what the measurements mean.

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