Why Email Warmup Matters for Your Deliverability

It’s harder than ever to get your email into an inbox — let alone get it opened.

Today, over 15% of emails never even make it past spam filters. And for GTM teams, that means deals are dead before they even get a shot.

That’s why we are integrating Email Warmup into Apollo to help sellers, marketers, and founders protect their sender reputation, improve deliverability, and generate pipeline more reliably. Here’s why we added it and what it means for your team.

Warmup workarounds aren't enough (and hurt your pipeline)

If you’re sending outbound email from a new domain or mailbox, your odds of landing in spam are high — by default. Email providers see new senders as unproven, and with the rise of stricter spam filters, even reputable teams can get flagged.

Enter Email Warmup: the process of gradually increasing your sending volume to build trust with inbox providers.

It’s an outbound sales task that pays back tenfold. But email warmup can be technical and complex, which often results in sales teams pushing it to the wayside.

Executing email warmup is a pain for most teams, because it's:

• Manual. It requires you to toggle settings, adjust volumes, and track reputation across multiple platforms.
• Disconnected. Many teams rely on tools that aren’t built into their workflow, adding complexity instead of clarity.
• Opaque. Most teams have little to no visibility into how their deliverability is actually performing.

We noticed these struggles across our customers. Apollo users were well aware of the importance of protecting their domains but were hacking together solutions like:

• Paying for third-party warmup platforms
• Installing Chrome extensions that often got shut down or flagged themselves
• Creating manual throttling systems in spreadsheets
• Or just sending and hoping for the best

These are short-term patches, not long-term answers. They add friction, fail silently, and introduce more tools into already crowded workflows.

That wasn’t good enough.

How Apollo Email Warmup works

By integrating warmup expertise directly into Apollo, we’re delivering something users could never achieve in one place:

• True automation to stop the juggling logins and manual adjustments to sender volumes.
• Workflow integration to make warmup a part of the same system you use to prospect and send
• Scalability — whether you’re onboarding one new SDR or launching five domains, it just works.

Apollo's Email Warmup is designed to be simple on the surface and powerful underneath. Here’s what we've added:

• SMTP-based warmup mimics real sender behavior
• Managed inbox network sends and receives warmup messages for you
• Automatic ramping and reply simulation builds trust with inbox providers
• [BETA] Ability to purchase domains and mailboxes without leaving the Apollo platform, removing one more step between idea and execution

Who has access? Paid users can warm up one mailbox at no additional cost. Additional mailboxes (for free or paid users) can be warmed using either Unified Credits or Export Credits, on a per-mailbox, per-month basis.

👉 Learn more about Apollo Email Warmup

What we’re seeing so far

In early access, teams using warmup have seen:

• Simplified tech stacks by eliminating the need for separate warmup tools
• Reduced spam flags and bounce rates across new domains
• Faster ramp-up times for new SDRs and mailboxes

One early user put it best:

Your emails deserve to be seen

When your emails don’t get delivered, it’s not just lost outreach.

It’s lost credibility, lost conversations, and lost time your team will never get back. And the toughest part? You often don’t know it's happening until the pipeline dries up.

Warming up your emails is the first step to getting ahead of deliverability issues, not just reacting after the damage is done.

With Apollo’s Warmup, you get:

• Fewer deliverability headaches
• Faster ramp-up for new mailboxes
• More pipeline from every campaign

You can expect even more new features, like domain health monitoring and real-time alerts, coming down the pipe!

👉 Learn more about Apollo's built-In Warmup. (Already have an Apollo account? Get started here.)