> For the complete documentation index, see [llms.txt](https://docs.windsor.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.windsor.io/integrations/klaviyo/prevent-duplicate-emails.md).

# Prevent duplicate emails

To prevent sending duplicate video emails to the same person, you can use Klaviyo's built-in "Flow filters". We highly recommend using these in your flows.\
You can set them up like this:

1: Select the flow you'd like to edit.

![](/files/LJpsKv1MzS1LL6ibuf7Y)

2: Click the "**Trigger**" box and select "**Flow filters**".

![](/files/fWko8OpmrkuV6OvtiS0c)

3: Click the "**Add a flow filter**" button.

![](/files/R3lLUkyYjmWZvLK0YqxQ)

4: Select "**Has not been in this flow**" from the first dropdown and leave the "at any time" box as-is.\
Click "**Save**" after that.

![](/files/DuL5ogI2UphYukNz014A)

That's it! These steps will prevent people from being added to this flow a second time.