Home  › Email › Email Marketing

Gmail Filtering: The Spam Disposition

  |  June 7, 2012   |  Comments

If you're getting filtered at Gmail, consider the reasons given and you may be able to more quickly remedy the situation. Part two in a two-part series.

This is the second of a two-part series on Google's spam filtering system and what the new messages teach us. In the first column I explained what Google has changed and looked at the phishing/forgery disposition and how to avoid it.

This week we'll examine the spam disposition. These are messages that Google has tagged as "Spam" not because they're fraudulent or forged (though they may be that) but because Google considers them to be unwanted by their intended recipient.

Like the phishing/forgery disposition, there are just a few reasons given for treating a message as spam. However, those few reasons have some important implications.

Messages that indicate this disposition include:

  1. It contains content that's typically used in spam messages.
  2. It's similar to messages that were detected by our spam filters.
  3. You previously marked messages from xxx@yyy.com as spam.

1. It contains content that's typically used in spam messages. For a while there content filtering was virtually dead. Spammers became very adept at avoiding keywords and phrases and at obfuscating their content. So much so that content filters often caught more innocent bystanders than actual spam.

Industry professionals have been saying for a while though that content filtering has seen a renaissance and here's proof. But this isn't the content filtering of yore. It's not just simplistic filtering of keywords and phrases but much more complex statistical analysis.What that means is that you're not likely to get filtered just for using a trigger word or phrase and you will be unable to determine whether a message will be filtered based on a list of trigger words or phrases. Unexpected content combinations may trigger content filtering and which ones may vary over time. So you must test your messages to see where they actually end up.

2. It's similar to messages that were detected by our spam filters. One could call this guilt by association. Google doesn't provide great detail as to what similarities it looks at but one can reasonably presume the usual suspects are involved.

Source. The Internet Protocol (IP) address the message came from. This may be considered with surrounding addresses (your Internet neighborhood). If other messages from the same address (or neighborhood) look like spam, yours may be classified that way too. This is particularly problematic for small senders on shared servers.

Headers. Particularly the From and ReplyTo addresses and domains. Splitting your email across multiple IP addresses or even email service providers (ESPs) may be given away by your domains and addresses.

Content. Beyond just keywords and phrases, links can be a cause of filtering. If URLs in your message are the same as or similar to that of spam emails, you may find your messages filtered.

3. You previously marked messages from xxx@yyy.com as spam. On the surface this is an obvious item, but there is some subtlety here that bears consideration.

As a recipient, of course you expect that all future email from a sender you marked as a spammer will be hidden from you. As a sender though, if you were not registered for a feedback loop or failed to process it properly, weren't sent the complaint notification, or with some ISPs if there is no notification, you will forever more be marked as spam for that recipient.

Once a relatively small number of users start marking your email as spam, the data shows that much or all of your email will start being bulked. Now consider the relationship of this rule with the similarity rule in item two and the negative impact these users will have on your engagement metrics. The more recipients on your list who have marked your message as spam in the past, the harder it's going to be for you to stay out of the spam folder in the future.

This may be a good reason to consider sunsetting long-term inactive users.

It's interesting to note also that while these reasons tell us a fair bit about Google's spam filtering, there is much that is left out. There is, for example, no mention of reputation even though we know reputation is heavily used by almost all major Internet service providers (ISPs). Clearly Google is trying to keep the explanations simple and accessible to the layman, but it's also keeping very quiet about the details of how it makes decisions in order to prevent spammers gaming the system.

All the same, if you're getting filtered at Gmail, consider the reasons given and you may be able to more quickly remedy the situation.

Until next time,




Derek Harding

Derek is the managing director of J-Labs, Javelin Marketing Group's technology skunkworks, a role that draws on his 20 years of experience and leadership in the fields of marketing and technology. A British expatriate based in Seattle, Washington, Derek is perhaps better known as the founder and technologist behind Innovyx, one of the first email service providers later acquired by the Omnicom Group. An industry veteran and thought-leader, Derek is a regular expert author, contributor, conference speaker, and takes an active role in a number of industry and trade groups.

COMMENTSCommenting policy

comments powered by Disqus

Get ClickZ Email newsletters delivered right to your inbox. Subscribe today!



Featured White Papers

US Consumer Device Preference Report

US Consumer Device Preference Report
Traditionally desktops have shown to convert better than mobile devices however, 2015 might be a tipping point for mobile conversions! Download this report to find why mobile users are more important then ever.

E-Commerce Customer Lifecycle

E-Commerce Customer Lifecycle
Have you ever wondered what factors influence online spending or why shoppers abandon their cart? This data-rich infogram offers actionable insight into creating a more seamless online shopping experience across the multiple devices consumers are using.




  • SEO Specialist
    SEO Specialist (Marcel Digital) - ChicagoSearch Engine Optimization (SEO) Specialist   Marcel Digital is an award winning digital marketing...
  • SEO / SEM Manager
    SEO / SEM Manager (CustomInk) - FairfaxAre you a friendly, motivated, and inquisitive individual? Are you a positive, out-going leader? Are you...
  • SEO Analyst
    SEO Analyst (XO Group) - New YorkSEO Analyst @ XO Group About this Job, You and Our Team: The XO Group SEO Team is looking for you, a passionate...