Emails to, and bouncing overnight

  • 31 January 2024
  • 5 replies


I manage three separate Klaviyo accounts for brands I work on and every single one has seen a massive spike in bounce rates basically overnight on January 22-23, from 0.3% to over 5%. The weird thing to me is they’re all,, and email addresses, all of which we were receiving emails just fine before January 22nd. 

My temporary solution is to just not send emails to anyone who has bounced, but Apple users make up a good chunk of our lists, so I don’t want to do this forever. Has this ever happened to anyone else? Are there any solutions for sending emails to these accounts? I am totally baffled.


Best answer by retention 31 January 2024, 17:28

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5 replies

Userlevel 7
Badge +58

HI @maddiebarbera, first, welcome to the community!

So, a few things you might want to check to troubleshoot - it does seem strange that it’s isolated to a particular inbox provider (Apple), and across all three different accounts, but this might give you some clues on what’s going on.

Check your Deliverability Bounce Detail Reporting

You can look at the accounts’ overall deliverability in the Sidebar → Analytics → Deliverability, then go to “Bounce details” in the secondary sidebar.  In the “Bounce report” section, select Apple as your “Inbox Providers” and see what type of bounce reasons that Klaviyo is finding.   

It might look something like this:

If you don’t see any reports, make sure you have a wide enough time period

In my example, there’s not enough incidents to find a conclusive reasons for those bounces, but yours may differ and you may be able to address them.

Other suggestions to consider:

  • Are all your brands on a branded sending domain yet?
  • Or, did you recently switch to one to be compliant with Google/Yahoo Bulk Sending?  Perhaps you’re getting caught into something algorithmic in a sudden change, and with high volume or frequency shortly after a change.
  • Is all the configurations (e.g. SPF/DKIM/DMARC) correct?  Some inbox provider may be more sensitive to updates or misconfigured settings.  I realize it’s unlikely all three accounts have these issues, but just verify.
  • Apple doesn’t have a feedback loop for Postmasters for the general public, but they do have some specific guidlines here.  You may want to take a look here: Postmaster information for iCloud Mail

Hope this helps!  Perhaps others can chime in with other suggestions or ideas.



Hi @retention - thanks for your response. Answers below:

  • Yes, all three accounts are on branded domains. 
  • I made changes to be compliant with Google & Yahoo’s send requirements several days after this issue started, so I don’t think they’re related. 
  • I have checked, double checked, and triple checked the SPF/DKIM/DMARC configurations and everything seems to be set up properly.
  • I reached out to Apple and have tried to check the things they suggest. 

I really don’t understand how it happened across three separate accounts all at once. My emails to these addresses are bouncing when sent from Shopify as well. I am at a loss...any extra info or suggestions of what to try next are much appreciated!

I have exactly the same issue. Sadly had to remove all Apple email addresses as my bounce rate was high. 

Following up on this. We have had the exact same thing starting last tuesday with our bounce rate reaching 5% all due to Apple related emails. All with the same 554 5.7.1 [cs01] message rejected due to local policy Which also provides zero insight into what is happening.

I have gone through much like OP here and have checked everything on our end there is nothing that should be causing this and all of the sudden as well. 

We set up branded domain in Klaviyo back in December and had zero issues until March 19th. All domain policies have been set and set correctly, Our Google Postmaster indicates no issues with reputation. MX Tools shows everything is good and not even blacklisted. 

Why would this start all of the sudden and seemingly at random. If it were one person I would say its isolated to their list, but clearly more and more people are being affected by this and can cause harm to our sending rep.

Need real answers. 

Userlevel 5
Badge +25

@KennSampson I checked internally with a deliverability expert and it’s definitely unusual for a bounce rate to be that high and also issuing from Apple. There isn’t a known issue going on with Apple domains. Bounces can happen for any number of reasons and variables that are unique to each domain and campaign. So, in order to properly diagnose this I suggest reaching out to our Support team. They’ll be able to dig into your account and campaigns and figure out what might be affecting your bounce rates and solutions to fix it!