Frequently Asked Questions

Everything you need to know about audience recovery with Rewarm.

What is a suppression list, and why is it worth revisiting?

A suppression list is a collection of email contacts that your ESP (like Klaviyo or Omnisend) has stopped sending to. These contacts typically end up suppressed for one of a few reasons:

Here's the thing: many of these contacts aren't actually "dead." They opted in at some point. Some of them purchased. Some are seasonal buyers who only engage a few times a year. Some just stopped opening emails but still recognize your brand.

Meanwhile, you're often still paying for them. Most ESPs charge based on total contacts, not just active ones. So you're paying to store people you're not allowed to email.

For most DTC brands, 30–50% of their total email list is sitting in suppression. That's a significant chunk of people who already know your brand — and a significant cost you're carrying without any return.

The question isn't whether these contacts have value. It's whether there's a safe way to find out.

Why does re-engaging suppressed contacts inside your main ESP cause problems?

When you send emails, inbox providers (Gmail, Yahoo, Outlook, etc.) are constantly evaluating your sender reputation. They look at signals like:

Your main ESP sending stream — the one you use for campaigns, flows, and regular marketing — has built up a reputation based on sending to engaged contacts. That reputation is what gets your emails into the inbox instead of the spam folder.

The problem with reactivation inside your ESP

When you try to re-engage suppressed contacts through your main ESP, you're mixing low-engagement sends into your high-engagement stream. Even if you create a separate segment or flow, you're still sending from the same domain and IP infrastructure.

The result:

This is why most retention teams are (rightly) afraid to touch their suppression lists. The risk to their core program feels too high.

How Rewarm is different

Rewarm operates on completely separate sending infrastructure — different domains, different IPs, isolated from your main ESP.

This means:

Think of it like a service road next to a highway. Your main email program stays fast and protected. Rewarm gives you a separate lane to carefully re-engage lapsed contacts without interfering with the main flow.

What is Senders, and what's the relationship with Rewarm?

Senders is an email infrastructure and deliverability company. We help businesses send email reliably — whether that's cold outreach, transactional messages, or marketing campaigns.

Our background is in B2B email deliverability, where the margin for error is razor-thin. We've spent years building and managing sending infrastructure for companies that depend on email reaching the inbox.

Rewarm is a service run alongside Senders, built specifically for DTC and ecommerce brands.

When we started working with consumer brands, we were surprised by how much of their audience was locked away in suppression. These weren't cold leads — they were opted-in contacts, often past customers, who had simply gone quiet. And brands were afraid to touch them because of deliverability risk.

We realized our infrastructure and expertise could solve this problem. Rewarm applies what we know about deliverability-safe sending to the specific challenge of audience recovery.

So when you work with Rewarm, you're getting:

How much does Rewarm cost?

Rewarm campaigns are priced based on two factors:

What you get

One-time or ongoing

You can run Rewarm as a one-time project to clear your existing backlog, or as an ongoing service that continuously catches new lapsed contacts as they appear.

We're currently running low-cost pilots with a small group of brands. If you'd like to explore whether Rewarm is a fit, get in touch and we'll walk you through the specifics for your situation.

Ready to explore?

Tell us about your suppression list and we'll see if Rewarm is a fit.

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