Why have your Mailchimp Open and click rates suddenly dropped?
There’s been a lot of panic over the last few weeks about why open and click rates have suddenly changed (mostly for the worst) in Mailchimp.
One day, they might have said 45% open rate, and suddenly they say 15%. Not just for recent campaigns, but past ones too.
What on earth has happened? Have you done something wrong? Are you blacklisted?
Well, in short, nothing bad has happened, it’s just that reported rates are suddenly more accurate.
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If you’re a regular reader of my articles, you might have seen the one back in June when I talked about why the opens and clicks in your Mailchimp reports couldn’t be relied upon. They have been getting increasingly inaccurate because of:
Apple devices reporting back that emails have been opened, regardless of whether they actually were
Firewall bots opening emails and clicking on links to see if they’re safe, before letting them through to human recipients. And those bots then sometimes stop human interaction being sent back,
Depending on who your audience is, those bots could have a HUGE impact on your reports, and very often lull you into a very false sense of security. For example, and D2C audience might be very mobile-based and impacted by Apple’s MPP, while a B2B audience of larger corporates, or schools (they’re a toughie) will have some tough firewall-bots between you and the humans on your list.
And it’s important to say here, this is not just Mailchimp, this is an industry-wide issue.
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The clever peeps at Mailchimp have been busy sorting that out.
As a Pro Partner, I get regular behind-the-scenes briefings and updates from Mailchimp about what’s going on, and what’s coming up.
As part of a briefing in October 2025 (I think), they said they were working hard on developing a new filter to help identify and remove bot activity from reports, so that they the stats we see a lot more accurate.
They’ve suddenly started rolling out the new feature out across accounts, and so we’re suddenly seeing changes - as it’s mid-roll out, reports are a little erratic and glitchy but it will settle down soon. Some of my clients’ account are not yet showing the change at all, some are showing it fully, some are seeing a random mishmash of data that doesn’t make any sense. But be patient, it will get there.
So if you were seeing 50% open rates, and they’re suddenly at 18%, nothing has changed about the way those emails were received or engaged with, it’s just that the reports are suddenly not skewed by bot activity. The stats you see are erring on the side of caution, but are much more accurate than before.
Here’s how to see if you have the new feature yet?
Go into a recent campaign report. Just above the main stats you’ll see one of two things:
A little green dot next to the words “Bot filtering on” - yes you have the new feature, or at least, it’s been activated in your account and might still be mid-propagation.
A little green tickbox next to the words “Exclude Apple MPP for more accurate open data” - no, it’s not yet active on your account, but will be soon.
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Unfortunately and frustratingly Mailchimp hasn’t yet communicated with everyone (including their customer support team) as to what is going on - I have no idea why, no doubt they have been inundated with panicked questions.
Some things remain unknown and will hopefully be sorted out soon. For example:
Will automated flow behaviours (e.g. if someone clicks do x, if not do y) take into account bot activity?
Will multivariate testing exclude bot activity when assessing a “winning” version?
Will historical analytics and custom reports be fully updated, or will there be a cut-off point, and if so, will that be obvious in reports?
Will bot activity be reflected in segments that contain behavioural factors e.g. subscribed over 100 days ago but has not opened an email in the last 30 days?
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In the meantime, you can modify the settings to include/exclude bot activity just to see how much of an impact it has on your reports - it can make a huge difference:
And don’t forget
The measure of an email’s success isn’t ultimately about the opens or the clicks - it’s about the enquiries, the replies, the conversions, the sales, the bookings, the survey responses etc etc. That should be your number 1 metric, which can’t always be even seen in Mailchimp. After all - the reports simply can’t tell you if someone read your email then phoned you up with credit card in hand.
Got questions? Need help?
Just ask me. I’m a Mailchimp expert Pro Partner ranked in the top 10 globally, with over 15 years’ experience, so there’s not much I don’t know!