Bounce handling simplified

I am a strong believer that bounce handling should be designed to remove addresses that have no human on the other end while not removing addresses that have a real recipient on the other end.
Bounce handling should be designed to appropriately manage your subscriber base. Delivery problems are the consequence if you don’t do that. They shouldn’t be the reason you bounce handle, though.
Context matters.
My experience tells me that senders that think about the impact of their sends can do things that “break the rules” while still being respectful of their subscribers and still see good delivery.

Email fingerprinting
Yahoo awarded $610 million

Related Posts

Reputation

Reputation is the buzzword in delivery these days. Everyone talks about building a good reputation and how to do it. Makes sense, the ISPs are always hammering on reputation and how critical reputation is. The more I talk with delivery folks on the ESP side of thing, the move I realize that there is a fundamental disconnect between what the ESPs mean when they say reputation and what the ISPs mean when they say reputation.
Many people handling delivery think that the bulk of reputation is wrapped up in complaint rates and bounce rates. I think they know the ISPs measure more than just complaints and bounces (spamtraps!) but really believe that most of developing a good reputation is all about keeping those complaints low.
This perspective may have been true in the past, but is becoming less true as time goes on. There are a lot of very smart people managing incoming mail at the ISPs and they are constantly looking for ways to better meet the desires of their customers. Lest we forget, their customers are not the senders, their customers are the end users. Their customers are not senders.
Part of meeting the needs of end users means actually giving them a way to provide feedback. AOL started the trend with the this-is-spam button, and other ISPs (ones that controlled the user interface at least) followed suit. For a very long time, reputation was dominated by complaint percentages, with modifiers for number of spamtrap addresses and number of non-existent users.
The problem is, these numbers were easy to game. Spammers could modify their metrics such that their email would end up in the inbox. In response, the ISPs started measuring things other than complaints, bounces and spamtraps. These other measurements are strong modifiers to complaints, such that mailers with what used to be acceptable complaint rates are seeing their mail end up bulked or even rejected.
Recently, AOL seems to have made some subtle modifications to their reputation scores. The result is mailers who have previously acceptable complaint rates are seeing delivery problems. When asked, AOL is only saying that it is a reputation issue. Lots of senders are trying to figure out what it is that is more important than complaints.
Tomorrow, I will talk about what I think AOL could be measuring.

Read More

AOL transmitting 4xx error for user unknown

AOL is currently returning “451 4.3.0 <invaliduser@aol.com>: Temporary lookup failure” in some cases when they really mean “550 user unknown.” This message from AOL should be treated as 5xx failure and the message should not be retried (if at all possible) and the failure should be counted as a hard bounce for list management purposes.
This is something broken at AOL’s end, and the guys with the magic fingers that keep the system running are working to fix it. Right now there doesn’t seem to be an ETA on a fix, though.
Even if you are a sender who is able to stop the retries, you may see some congestion and delays when sending to AOL for the time being. Senders who don’t get the message, or who are unable to stop their MTAs from retrying 4xx mail will continue to attempt delivery of these messages until their servers time out. This may cause congestion for everyone and a noticeable  slowdown on the AOL MTAs.
AOL blog post on the issue
HT: Annalivia

Read More

What's the best ESP?

I often get clients and potential clients asking me to tell them what the absolute best ESP is.
“You’re an expert in the field, which ESP will give me the best inbox delivery?”
The thing is, there isn’t an answer to that question.
ESPs have expertise in sending large amounts of mail.  All have staff that manage and monitor MTAs. Most have staff that provide advice on delivery issues. Many have staff that handle abuse complaints, FBLs and blocks.
What they don’t have is magic delivery fairies or bat phones into postmaster desks.
Simply moving mail to an ESP won’t give you delivery. For the most part, delivery is the responsibility of the sender, whether they send mail through an in house system or through an ESP.
Delivery is primarily about how recipients react to a particular mail stream. Send mail recipients want, interact with and relate to and you usually see good delivery. The IP addresses or infrastructure contribute but do not dominate the equation. Sending from an ESP won’t fix poor content, irrelevant mail or unengaged recipients.
I can hear everyone now shouting at their screen “What about shared IPs!!!?!?!” Yes, yes, if you use an ESP with shared IP addresses and the ESP gets a bad customer you may see poor delivery for a time because one of their other customers was bad. It’s a fact, it happens. Plus, if you use an ESP with dedicated IPs and the ESP gets a bad customer you may see poor delivery for a time because one of the other customers was bad and their IP is near yours.
So clearly the answer is to bring email in house. That way no other company can affect your delivery, right? Yes. Kinda.
Are you willing to invest money in hiring email and DNS savvy sysadmins? Invest money in a MTA designed to handle bulk mail? Invest in an expert who not only understands bounce handling, but can explain to your developers what a good bounce handling system must do? Invest in someone who can manage authentication like DKIM? Who can handle delivery issues and understands how to talk to ISPs? Invest in development to write a FBL processor?
For some companies, the internal investment is the right answer, and bringing mail in house makes business sense.
For a lot of companies, though, they just want to use email to communicate with customers. They don’t want to have to invest in multiple staff members (as it’s very rare to find a single person with all the various skill sets needed) to just send a weekly newsletter, or daily sales email. They need a tool that works, they don’t need to know how to sign up for a FBL, they don’t need to know how to handle bounces. They can outsource that work and focus on the communication value.
Finding the best ESP starts with finding out how you want to use email.
Question 1: What role does email play in my business?

Read More