What you need to know about email marketing and spam filters

Let’s talk about spam filters. You know, the ones that are clicking all the links in your outbound emails to check for spam? They’re messing with reporting, lead scoring and causing all kinds of problems.

It's an issue that we starting seeing in 2015, but this year these spam systems are getting more aggressive and sophisticated. So bad in fact, that often spam filter clicks can make up over 50% of the total clicks to emails.

Here are the key points to know about what is happening:

  • Spam filters are clicking links in emails to check for malware and it is likely that they target senders with a bad reputation and/or emails with content that triggers the extra check

  • Old solutions for this issue are not working any more. It used to be that you could filter out “bad” clicks, because the system would click all links in the email or click then not visit the web page. So you could add an invisible (to humans) link and if it's clicked you know it's the spam system. Or you could filter out people who didn't visit the webpage after clicking. Unfortunately it seems like the system is now clever enough to only click the CTA once and sometimes it even visits the web page. Some people even report that the form gets filled out (if there is one).

  • It seems the best way to detect a spam blocking system is with timing. When looking through each lead record you'll see they are clicking every single email, with a click immediately after the email was sent. The problem is, there is no way to filter for this and you may filter out real clicks. Plus there are even reports of the systems clicking a few minutes after the email send.

Potential issues that arise because of this:

  • Unqualified leads. When using un-gated content in emails, if you use clicks to track downloads, then these "fake" clicks will count the lead as as converted, potentially qualifying them as an MQL, when in reality they didn't do anything. This could lead to issues with your SDR team no longer trusting your leads. To get around this, consider gating your content. You can use progressive profiling to shorten the form. Then instead of scoring email clicks, you can score when real person downloads your content thanks to the form fill.

  • Email deliverability. If you are seeing these spam system clicks triggered, something is indicating to those spam filters that you are not a trusted source. Learn what attributes Barracuda looks for in this article. Then, check out these great recommendations from Pardot on how to improve your email marketing’s spam factor.

  • Email reporting. When reviewing email performance by tracking opens and clicks, take it with a grain of salt. There are several factors that contribute to numbers being off, including spam filters but also things like like type of email client. Instead of fixating on email numbers, focus more on bigger picture reporting like the number of inbound inquiries attributed to a campaign.

Overall, following email marketing best practices will help you maintain your reputation as a sender. Just remember the golden rule, “Email others the way you would like to be emailed yourself.” If you have any experience or best practices for this situation, we would love to hear about it in the comments.


Further reading:

Check out the discussion about this topic in the Marketo Community.