Retention.com is designed to send you net-new contacts only — people not already in your email platform.
How this works depends on how you're set up.
If you're using a connected email platform
This is handled automatically for the following platforms:
Klaviyo
ActiveCampaign
Beehiiv
Brevo (formerly Sendinblue)
Campaigner
Dot Digital
Drip
GetResponse
HubSpot
Iterable
Mailchimp
Maropost
Omnisend
We check your email platform before adding new contacts:
If the contact already exists → we don't collect them → you're not charged
Make sure "Exclude existing contacts" is toggled to ON (it is by default).
How to avoid sending to contacts you already have (custom setups only)
If you're using Webhooks or Webhook Grow, automatic exclusion does not apply. Upload your existing contacts so they can be excluded.
Important to know
This isn't just about cost control. If a contact you already have gets passed through as net-new, they may be treated as a new contact in your email platform, which means they could receive messaging that doesn't match where they actually are with your brand. This ensures you're only paying for, and only acting on, truly new contacts.
What to do next
Using a custom setup (Webhooks or Webhook Grow)? → Upload your existing contacts
Using a connected platform? → You're all set — no action needed