WARM BEFORE YOU SEND  //  reputation is earned slowlyApply
EMAIL WARMUP

Warm the mailbox before you send.

Warmup is the quiet step that decides whether your cold email reaches the inbox. Skip it and a new mailbox looks like a spammer on day one. Here is what it is and how to do it right.

Line-art of mailboxes warming up along a rising ramp from cold to warm
THE SHORT ANSWER

Email warmup gradually ramps a new mailbox's sending, paired with automated positive engagement, so providers trust the sender before real campaigns begin. Plan for two to four weeks of ramp, then keep a lighter warmup running underneath live sending. Reputation is earned slowly and lost fast.

What warmup actually is

When a mailbox is brand new, mailbox providers have no history to judge it by. Warmup gives them that history on purpose: the mailbox sends a small, growing number of emails that get opened, replied to, and marked important, so providers learn it behaves like a real person rather than a spam source. Only once that trust exists does cold outreach reliably reach the inbox.

Why skipping it fails

Sending cold email at volume from a cold mailbox is the single fastest way into the spam folder. Providers watch for sudden volume from unknown senders, and they treat it exactly like the spam it resembles. No subject line or copy can save an unwarmed mailbox, which is why warmup comes first, always.

A sensible ramp

Stage
Per mailbox / day
What is happening
Week 1
~5-10
Warmup engagement only, no real campaign yet
Weeks 2-4
~10-30
Gradually increase as reputation builds
Steady state
~20-50
Conservative cruising rate for real campaigns
During campaigns
keep warmup on
A lighter warmup runs underneath to hold reputation

Warmup is ongoing

The mistake is treating warmup as a one-time task. Reputation drifts as volume changes and mailboxes age, so a steady amount of warmup engagement should keep running underneath live campaigns. Combined with low per-inbox volume, dedicated domains, and full authentication, it is what keeps deliverability high over months, not just weeks. For how much to send once warmed, see how many cold emails per day.

FAQ

Common questions.

What is email warmup?+
The process of gradually ramping up sending from a new mailbox, paired with automated positive engagement, so mailbox providers build trust in the sender before real campaigns begin. It signals the mailbox belongs to a legitimate sender rather than a spammer.
Why do new mailboxes need warmup?+
A brand-new mailbox has no sending reputation. If it immediately blasts cold email at volume, providers treat it like spam and filter it. Warmup builds reputation slowly so that when campaigns start, the mailbox is trusted and lands in the inbox.
How long does warmup take?+
Plan for roughly two to four weeks of ramp before running real campaigns, then keep a lighter warmup running underneath live sending. Rushing warmup is one of the most common reasons cold email ends up in spam.
Should I keep warmup running during campaigns?+
Yes. Keeping a steady amount of warmup engagement running underneath live campaigns helps maintain reputation over time, especially as volume changes. Warmup is not a one-time step, it is ongoing maintenance.
How much can a warmed mailbox send?+
After warmup, a conservative cold-sending rate is roughly 20 to 50 emails per mailbox per day. Total volume scales by adding more warmed mailboxes, not by pushing a single inbox harder.

We warm and run it for you.

Dedicated domains, warmed mailboxes, and monitoring, handled end to end so your campaigns reach the inbox. Revenue-share, so we win when you win.

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