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tooltester
Contributor I
Contributor I
Apr 22, 2026 1:38 PM UTC

Free Chrome extension that shows which of your competitors are using Klaviyo too (or other tools)

Quick share: I made a free Chrome extension that shows you which ESP sent any newsletter in Gmail.

So when you get, for example, a competitor's newsletter, you instantly see if they're on Klaviyo too, or Mailchimp, ActiveCampaign, or something else.

It also tells you if they're on a shared or dedicated IP and whether their authentication (SPF/DKIM/DMARC) is set up correctly. Handy if you want to check how you or other senders have their setup configured.

It's free on the Chrome Web Store. No data leaves the browser. Feedback is welcome.

    2 replies

    Kim from Cadence
    Partner
    Partner
    Apr 29, 2026 1:45 AM UTC

    Neat! This seems useful for Klaviyo partners looking to sell to Klaviyo brands. 

    Cadence / Book a demo

    Kim — Founder @ Cadence | Helping brands automate recurring campaigns (daily, weekly, monthly) | Happy to connect! | https://cadencecampaigns.com
    tooltester
    Contributor I
    Contributor I
    Apr 29, 2026 7:32 AM UTC

    You could also use it to lure away current Mailchimp ecommerce customers 😉