Filtering changes at Gmail

UPDATE: Towards the end of February 2019, customer reports of transactional messages going to the spam folder decreased dramatically. Gmail appears to have made significant improvements to their automated filtering that now minimize this issue.



In the past couple of weeks, we’ve seen multiple customers report that their messages to Gmail/GSuite recipients are suddenly delayed, ending up in the spam folder, or just missing entirely.

As I’ve been working with Google to understand the issue, yesterday they posted an update. It publicly confirms the widespread changes they've made to substantially increase spam blocking, which were rolled out at the end of January.

I've been tracking and testing these cases affected by the changes, and here’s what I know so far:

  • It affects senders indiscriminate of high or low volume/reputations.
  • There’s no identifiable trend in the messages' sending settings or content.
  • In many cases, we see the same delivery issues when testing in other ESPs.

So why aren't other ESPs talking about this? #

First, Postmark is unique in that we have a pretty strict transactional-only message policy. We even have actual humans vetting each new account to ensure our sending reputation is top-notch. That means we're not used to seeing Gmail issues, so just a handful of these cases makes a pretty big blip on our radar. Second, Google is specifically targeting spoofing/phishing, so it makes sense transactional traffic would be hit the hardest with false-positives. Stuff like password-resets, invoices, etc. are more likely to be modeled for these kinds of attacks.

What can you do about it? #

At the moment we just need to wait for Gmail to update their systems. As always, submitting examples of messages incorrectly routed to spam could help improve these filters faster and more effectively.

I'll also mention that a handful of Postmark customers had success getting back into the inbox by changing their authentication (sub)domains. We already know that domain reputation is a huge deliverability factor, so I think in these specific cases the reputation shift temporarily minimized the significance of other flags in the message, making it less susceptible right now to these new filters.

It's important to note this issue only seems to be affecting specific senders, not everyone nor every message. The best way to tell if your own messages are affected is to watch your Gmail engagement rates. Opens and clicks are directly tied to inbox placement, so noticeable shifts there could indicate an issue. If you'd like some assistance analyzing your traffic, give our Customer Success Team a shout. In the meantime, I’ll keep you updated here if anything else develops.

Anna Ward

Anna Ward

Head of Deliverability. I'm a professional picnicker, mediocre bourbon drinker, novice watercolor painter, and a fan of the Oxford comma.

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