Gmail filtering in a nutshell

Gmail’s approach to filtering; as described by one of the old timers. This person was dealing with network abuse back when I was still slinging DNA around as my job and just reading headers as a hobby.

Gmail uses a 10+ year old neural network that analyzes thousands of factors, related to email, IP, and web, integrated with all Google products, and with 99.9%+ accuracy for identifying certain types of messages, combined with an email-specific domain-based reputation system that combines IP reputation, content, read rates, reputation of other senders with similar content.

This excerpt was shared with a bunch of delivery experts and every one of them agreed. The Gmail filters are incredibly complex and they measure thousands of different things about email. Yes, sometimes you can remove a link or a URL and get mail to the inbox for a while. That doesn’t mean the block was against the URL, simply that changing the URL changed the score enough for the mail to go to the inbox.
This is part of what makes Gmail delivery issues so difficult to troubleshoot. There isn’t one thing, it’s all the things that contribute to where an email ends up. We, as senders and deliverability experts, don’t have access to the Gmail data. The poster goes on to say:

Trying to fix this using only inaccurate proxy data where there is no mediation pathway in a matter of weeks is complex.  We consume data from a multitude of sources, compile and analyze the data, determine which of the hundreds of factors we can influence should be adjusted, come up with the easiest plan to address the most influential factors, and explain that to the customer using the clearest language possible to individuals who are not educated on the definition of a complaint.

We do our best, with limited data and try and tell you how to fix things.
One of the biggest challenges with Gmail delivery is I am convinced they look at your profile of recipients. They can map someone who is collecting addresses through third parties, or buying lists based on the specific Gmail accounts targeted by a mailing. Gmail has publicly stated and has on their website that they don’t think co-reg or purchased lists are opt-in. They have the technology and ability to track that. I think it’s one reason senders trying to use email for acquisition have such a challenge getting into the inbox and Gmail. I think it’s a feature, not a bug for them.
 

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ISPs speak at M3AAWG

Last week at M3AAWG representatives from AOL, Yahoo, Gmail and Outlook spoke about their anti-spam technologies and what the organizations were looking for in email.
This session was question and answers, with the moderator asking the majority of the questions. These answers are paraphrased from my notes or the MAAWG twitter stream from the session.
What are your biggest frustrations?
AOL: When senders complain they can’t get mail in and we go look at their stats and complaints are high. Users just don’t love that mail. If complaints are high look at what you may have done differently, content does have an effect on complaints.
Outlook: When we tightened down filters 8 years ago we had to do it. Half of the mail in our users inbox was spam and we were losing a steady number of customers. The filter changes disrupted a lot of senders and caused a lot of pain. But these days only 0.5% of mail in the inbox is spam.  Things happen so fast, though, that the stress can frustrate the team.
Gmail: Good senders do email badly sometimes and their mail gets bulked. Senders have to get the basic email hygiene practices right. Love your users and they’ll love you back.
What’s your philosophy and approach towards mail?
AOL: There is a balance that needs to be struck between good and bad mail. The postmaster team reminds the blocking team that not all mail is bad or malicious. They are the sender advocates inside AOL. But the blocking team deals with so much bad mail, they sometimes forget that some mail is good.
Yahoo: User experience. The user always comes first. We strive to protect them from malicious mail and provide them with the emails they want to see. Everything else is secondary.
Gmail: The faster we stop spam the less spam that gets sent overall. We have highly adaptive filters that can react extremely quickly to spam. This frustrates the spammers and they will give up.
Outlook: The core customer is the mailbox user and they are a priority. We think we have most of the hardcore spam under control, and now we’re focused on personalizing the inbox for each user. Everyone online should hold partners accountable and they should expect to be held accountable in turn. This isn’t just a sender / ESP thing, ISPs block each other if there are spam problems.
What are some of your most outrageous requests?
We’ve been threatened with lawsuits because senders just don’t want to do the work to fix things. Some senders try to extort us. Other senders go to the advertising execs and get the execs to yell at the filtering team.
Coming to MAAWG and getting cornered to talk about a particular sender problem. Some senders have even offered money just to get mail to the spam folder.
Senders who escalate through the wrong channels. We spent all this money and time creating channels where you can contact us, and then senders don’t use them.
Confusing business interests with product interests. These are separate things and we can’t change the product to match your business interest.
What are your recommendations for changing behaviors?
Outlook: We provide lots of tools to let you see what your recipients are doing. USE THE TOOLS. Pay attention to your recipient interaction with mail. Re-opt-in recipients periodically. Think about that mail that is never opened. Monitor how people interact with your mail. When you have a problem, use our webpages and our forms. Standard delivery problems have a play book. We’re going to follow that playbook and if you try to get personal attention it’s going to slow things down. If there’s a process problem, we are reachable and can handle them personally. But use the postmaster page for most things.
Gmail: Get your hygiene right. If you get your hygiene right, deliverability just works. If you’re seeing blocking, that’s because users are marking your mail as spam. Pay attention to what the major receivers publish on their postmaster pages. Don’t just follow the letter of the law, follow the spirit as well. Our responsibility, as an ISP, is to detect spam and not spam. Good mailers make that harder on us because they do thinks that look like spammers. This doesn’t get spammer mail in more, it gets legitimate mail in less. Use a real opt-in system, don’t just rely on an implied opt-in because someone made a purchase or something.
Yahoo: ESPs are pretty good about screening their customers, so pay attention to what your ESPs are saying. Send mail people want. Verify that the email addresses given to you actually belong to people who want your mail. Have better sender practices.
What do you think about seed accounts?
The panel wasn’t very happy about the use of seed accounts. Seeds are not that useful any longer, as the ISPs move to more and more personalized delivery. Too much time and too many cycles are used debugging seed accounts. The dynamic delivery works all ways.
When things go wrong what should we do?
AOL: Open a ticket. We know we’ve been lax recently, but have worked out of our backlog and are caught up to date. Using the ticketing system also justifies us getting more headcount and makes everyone’s experience better. Also, don’t continue what you’re doing. Pausing sending while you’re troubleshooting the issue. We won’t adjust a rep for you, but we may be able to help you.
Gmail: Do not jump the gun and open a ticket on the first mail to the spam folder. Our filters are so dynamic, they update every few minutes in some cases. Be sure there is a problem. If you are sure you’re following the spirit and letter of the sender guidelines you can submit a ticket. We don’t respond to tickets, but we work every single one. When you’re opening a ticket provide complete information and full headers, and use the headers from your own email address not headers from a seed account. Give us a clear and concise description of the problem. Also, use the gmail product forum, it is monitored by employees and it’s our preferred way of getting information to the anti-abuse team. Common issues lots of senders are having will get addressed faster.
Outlook: Dig in and do your own troubleshooting, don’t rely on us to tell you what to fix. The support teams don’t have a lot of resources so use our public information. If you make our job harder, then it takes longer to get things done. But tell us what changes you’ve made. If you’ve fixed something, and tell us, our process is different than if you’re just asking for a delisting or asking for information. When you’ve fixed things we will respond faster.
How fast should users expect filters to respond after making changes?
Filters update continually so they should start seeing delivery changes almost immediately. What we find is people tell us they’ve made changes, but they haven’t made enough or made the right ones. If the filters don’t update, then you’ve not fixed the problem.

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Thoughts on Gmail filtering

Gmail has some extremely complex filters. They’re machine learning based and measure hundreds of things about incoming mail. The filters are continually adjusting to changes and updating how they treat specific mail.
One consequence of continually adjusting machine learning filters is that filtering is not static. What passes to the inbox now, may not pass in a couple hours.
One of the other challenges with Gmail filters is that they look at all the mail mentioning a particular domain and so affiliate mail and 3rd party mail can affect delivery of corporate mail.
The good news is that continually adjusting filters adapt to positive changes as well as negative ones. In fact, I recently made a segmentation suggestion to a client and they saw a significant increase in inbox delivery at Gmail the next day.
Gmail can be a challenge for delivery, but send mail users want and mail does go to the inbox.

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Thoughts on Gmail and the inbox

Over the last few months more and more marketers are finding their primary delivery challenge is the Gmail inbox. I’ve been thinking about why Gmail might be such a challenge for marketers. Certainly I have gotten a lot of calls from people struggling to figure out how to get into the Gmail inbox. I’ve also seen aggressive domain based filtering from Gmail, where any mention of a particular domain results in mail going to the bulk folder.
It’s one of those things that’s a challenge, because in most of these cases there isn’t one cause for bulk foldering. Instead there’s a whole host of things that are individually very small but taken together convince Gmail that the mail doesn’t need to be in the inbox.
A pattern that I’m starting to see is that Gmail is taking a more holistic look at all the mail from a sender. If the mail is connected to an organization, all that mail is measured as part of their delivery decision making. This is hurting some ESPs and bulk senders. I’ve had multiple ESPs contact me in the last 6 months looking for help because all their customer emails are going to bulk folder.
Gmail’s filtering is extremely aggressive. From my perspective it always has been. I did get an invite for a Gmail account way back in the day. I moved a couple mailing lists over to that account to test it with some volume and discussion lists. I gave up not long after because no matter what I did I couldn’t get gmail to put all the mail from that list into the tag I had set up for it. Inevitably some mail from some certain people would end up in my spam folder.
Gmail has gotten better, now they will let you override their filters but give you a big warning that the message would have been delivered to spam otherwise.
Gmail_NotSpam
What are mailers to do? Right now I don’t have a good answer. Sending mail people want is still good advice for individual senders. But I am not sure what can be done about this ESP wide filtering that I’m starting to see. It’s possible Gmail is monitoring all the mail from a particular sender or ESP and applying a “source network” score. Networks letting customers send mail Gmail doesn’t like (such as affiliate mail or payday mail, things they mentioned specifically at M3AAWG) are having all their customers affected.
I suspect this means that ESPs seeing problems across their customer base are going to have to work harder to police their customers and remove problematic mail streams completely. Hopefully, ESPs that can get on the Gmail FBL can identify the problem customers faster before those customers tank mail for all their senders.

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