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Why is my email in the spam folder?

One of the most common questions we get asked is why is my email in the spam folder. We do understand the confusion and frustration that comes with this issue,...

One of the most common questions we get asked is why is my email in the spam folder. We do understand the confusion and frustration that comes with this issue, and whilst we are unable to provide an exact reason why we can definitely assist in trying to narrow down the possible cause.

Why do you not know?

First, let’s look at the number of emails going around – while exact figures vary, it’s easy to say that this is going to number somewhere in the billions, if not more. For example, according to Gmail, in 2019 there are 1.5 billion active Gmail users worldwide and this is just Gmail alone. If each of those active users sent an email on any given day, that’s 1.5 billion emails on that day alone. That’s a lot of emails.

Second, let’s look at the spam problem. M³AAWG, an industry body group on senders and receivers conducted a study in 2007 and considers approximately 85% of given email traffic is most likely spam. This means that if those 1.5 billion active Gmail users receive a message each, 1.275 billion of those messages would most likely be spam.

Furthermore, At Gmail, by utilizing TensorFlow, a filter already on top of their existing protection, they blocked an additional 100 million additional spam messages each day on top of what they are already receiving. Given the volume, the complexity becomes exponential and fighting spam becomes a massive challenge – and any such clues that may render a filter useless to the protection already in place equate to an opportunity to be exploited by spammers.

Filters and spammers: marketers caught in the crossfire

Whilst this sounds difficult, there is good news, and that is usually these spam filters are very accurate. At Gmail for example, their existing filters block 99.9% of the spam. So this means that it is the sender’s responsibility to follow best practices, as, in turn, it proves to mailbox providers that your messages are legitimate.

As a sender, you may have experienced this occasionally, usually in the form of a drop in metrics such as delivered and engagement rates. But there is no need to panic, and while a tiny portion of this is an actual false positive, most of the time marketers just need to do a bit of work to revise and differentiate themselves from spammers as legitimate senders.

Getting out of the spam folder

The short answer is to revise your email marketing program. You can do so by starting with content, code, followed by how you manage your mailing list, as well as how well you are complying with deliverability best practices.

Content, for example, means creating content that is relevant and engaging for the recipient. Specifically, remember what expectations you set for the recipient when they were signing up. If the recipient engages in a positive way such as Opens, Clicks, Marks the message as Not Spam, mailbox providers will respect that decision. Even better if the recipient adds your address to their safe list.

From a coding perspective, if you have any 3rd party links within your email that do not link to a reputable source (i.e. the destination domain is not regionally/globally recognized by a typical recipient)- best to remove them, as filters may think of it as a phishing attempt.

As for list management, revise how you are managing it from acquisition to exit. Are you acquiring email addresses via a proper opt-in process such as a sign-up form on your website, not purchasing lists? Is your sign-up source secure so it does not get abused by spammers? Are you segmenting and suppressing those who do not engage with your email? While it does not sound pleasant when you want to grow your list and/or want to reach a wider audience, proper list management is essential to any email marketing program.

Finally, for deliverability best practices, these guidelines provide the best chances of your messages going to the inbox. Double-check how compliant your email marketing program is to the guidelines available. Are you going above and beyond? Are you honoring unsubscribe requests promptly? How are you handling complaints? All these factors add up and will influence the destination of your email.


Mailbox providers’ focus is on protecting their customers and their infrastructure from spam whilst letting legitimate messages through. Given the volume and the complexity, there are false positives on rare occasions but nearly all of the time, the cause of spam folder placement lies with the sender. Whilst it is confusing and frustrating, this is yet another perfect opportunity to revise your email marketing program, especially if you start noticing your messages being sent to the spam folder.

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