Blacklist domains

  • 28 November 2020
  • 14 replies

Userlevel 1
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First post :D

I have looked around in the help docs but couldn’t find any details on this… Is it possible to add a blacklist of domains we don’t want to accept subscribers from? I think it would be a very cool feature to avoid spam traps, scrappers (like Milled) and others.

Thanks in advance!


Best answer by Melissa.Matusky 30 November 2020, 14:49

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14 replies

Userlevel 2
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@Platanomelóm welcome to Klaviyo Community! :slight_smile:

Thanks for the feedback & ideas! Klaviyo doesn’t currently have the ability to block people from subscribing to your account based on domain, but we do have other tools that help maintain list health.

Klaviyo’s double opt-in process requires users to confirm their email before being added to your list and after they intitally fillout your signup form. Enabling this feature is a great way to ensure spam traps from entering your newsletter list.

Additionally, Klaviyo’s segmentation capabilities can collect email addresses you don’t wish to include in your regular sends. Simply use the condition “Properties about someone” > Email> contains> the particular email domain you wish to exclude. Here is an example of that segment definition

You can collect multiple domains by using an “OR” connector. 

Userlevel 1
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Thanks Melissa! I ended up creating a segment for those e-mails and then acivtating a notification flow to alert me each time someone joins that segment, so I can go manually and clean it :)

Userlevel 2
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@Platanomelóm love the idea of setting up the alerts for when these domains subscriber to your list! It's a great way to both clean out the list and keep an eye on how frequently these emails come into the account.

Userlevel 6
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Agree with @Melissa.Matusky that creating a segment and using the notification flow for alerts is a great way to go about it! Thanks for sharing this tip with the Community @Platanomelóm


I’d much rather have a blacklist domain option so it is fool proof. Surprised there is not an account setting level available. I’d think a lot of people would adopt this instead of always having to exclude a segment that includes them, or remember to exclude them from each segment. Then if you ever need to edit the blacklisted domains, you have to do it in every segment which sounds like zero fun. Features=Flexibility=Speed=Cost/Time Savings=Better Software=Happier Clients...

Userlevel 7
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@stouchette - Generally agree with your sentiments. But for what it’s worth, as a general workaround, I recommend my clients to build a master “Exclude Segment” with all the possible “global” exclusion reasons (outside of Suppression) and then include that Segment in all Campaigns/Flows to exclude.

Then we build a Flow, triggered by that Segment that uses the “Update Profile Property Action”  to set a custom profile property like is-exclude = true (or some string of text like “bot” or “amazon”).  

In all Campaigns we can use the first Segment to exclude from Campaigns.  (Yes, it’s an extra step). 

In all Flows, we use the is-exclude is not set as a Flow Filter so they don’t get any Flow messages.  

In this way, we don’t have to replicate that rule to every other Segment to ensure those profiles don’t receive messages.  We also use that Segment to occasionally suppress them manually (export into Profile → Suppressed Profiles,  Upload File Button), or delete them entirely in Profile Maintenance (Account → Settings → Profile Maintenance). 

When we find a new domain (or a new rule) to exclude, we just append to that Segment as an additional OR rule. 

Definitely a bit of up front effort here, no doubt, but it’s a one-time process and thatSegment is like our “Global Blacklist” so we don’t have to update it in more than one place. 

Userlevel 7
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Hello @stouchette,

Appreciate the feedback you’ve shared surrounding the ability to blacklist based on a domain. I’ll be sure to share this insight with our Product Team. 

Also, thank you @retention for sharing such a detailed strategy and use case examples as a workaround highlighting the creation of an “Exclude Segment” to be used in all your campaigns and flows! Sounds like a great scalable solution by simply adding more OR conditions to the segment to include new domains you’ve highlighted after initially building the segment out!



Dear Guys, i hope you can help us with an extremely important issue as we are in the midst of an litigation with a prosecutor that now reached cease-and-desist declaration against us to avoid any further mails being send to him. The accusation in general contains the point that he a) reproached us that we send him an unwanted double opt in mail (which is impossible to proof how typed in a mail adress into one of our signup funnels) and b) that our double opt in mail contained promotional aspects that is against German law (which is not the cause). The whole claim is really fraudulent but the court declared the cease-and-desist declaration, that we are not allowed to send ANY mail to the customer anymore. 

As we could blacklist the mail address for sendouts through all our flows, Klaviyo claimed now that they are unable to avoid a sendout of a double opt in mail to the customer if his email address would be typed in in any given sign up form again. And this double opt in mail would then violate the cease-and-desist declaration. So we are in a very bad sport against a fraudulent case and we thus needed to deactivate all our signup forms due to the legal case as Klaviyo wouldnt be able to prevent a blacklist for mail addresses that are typed into a sign up form.


Does anyone had this issue every before and has a work around how we could still keep the signup forms and Klaviyo but blacklist that no double opt in mail would be able to be send to a given email address?


This is a very business critical issue so we hope to get your help and thoughts. Thanks

Userlevel 7
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Hello @pkehela_mokebo,

I’m sorry to hear about the situation you’re in. 

The Community forum is a space for Klaviyo Customers, partners and other users to network and learn from one another. With a situation this serious, you’ll want to work directly alongside your legal council. 

It sounds like you’re already in contact with our wonderful Support colleagues. I’ll have to agree with them that there wouldn’t be a method to blacklist someone from receiving a double opt-in email. This is because double opt-in emails are sent out in response to the actions that your customers take. In this case, filling out a form and/or taking the action to subscribe to a list. 

Since this is an action that your customers are taking themselves, there really wouldn’t be a method on Klaviyo’s end to stop them. 

That said, one suggestion I can recommend would be using your own custom signup forms. Instead of preventing a double opt-in from being sent out, you can use a custom signup form to prevent certain individuals from filling out the form.

This in turn will prevent someone from receiving a double opt-in email as they never fully subscribed to make it on the list at all. 

Because custom signup forms are flexible, their behavior will really depend entirely on how you build them. I would suggest working alongside your developer or reaching out to some of our wonderful Klaviyo Partners who can help. 


Dear @David To thanks for your feedback on our situation. 
I am a colleague of Philip and have a few followup questions on custom signup forms, that you may help us with.
I found this article:
Would this be the right approach? Does the term legacy form refer to custom built forms or does it mean something else? 
I am wondering if there is a way to recode/insert something into our existing signup form or if we need to completely rebuild each signup from scratch using the legacy form?
If you have any further help articles on how to build customs signup forms please share them with us. 
Thanks in advance and kind regards!

Userlevel 7
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Hey @giannagnv,

You’re certainly on the right track! The term custom signup forms and legacy signup forms are synonymous with one another. 

The decision to recode/insert something into your existing signup form or to rebuild each signup form from scratch via HTML would depend entirely on your signup forms. Oftentimes though, I suggest going the full custom route. That way you can ensure the signup form is working and behaving as intended.

In addition to that How to add and customize a legacy embedded signup form Help Center article, I would recommend checking out similar articles on this topic:



Thank you @David To :) 

Hey dear @David To checking in once again to ask if you can recommend anyone of the Klaviyo Partners you mentioned who is experienced with custom sign up forms. Thanks! 

Userlevel 7
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Hey @giannagnv,

I don’t have any specific recommendations of our Partner’s program. I would suggest narrowing down your search using the available filters and potentially reaching out to several individuals.