The email warmup tool that builds your sender reputation, automatically.

How email warmup works

Warm up in three steps. Send cold without regret.

1. Connect
   Your inbox: tomas@leadroot.com — Gmail
   maria@alveo.io — Outlook
   sam@northpath.co — Google Workspace

   Connect your sending inbox

   OAuth into Gmail, Outlook, or any SMTP. Works for brand-new domains and established ones alike.

2. Warm

   Our network opens & replies

   30,000+ real inboxes exchange natural-looking email with yours — opens, replies, and stars. No fake traffic.

3. Track
   Deliverability: 93%
   Sender reputation: Strong
   Warmup strategy: 4/5

   Watch reputation climb

   Track inbox, spam, and bounce rates in real time. DNS, SPF, DKIM, and blacklist checks are built in.

Why use email warmup?

• Land in the primary inbox, not spam
  Email warmup builds the engagement signals providers reward, so your cold campaigns reach the primary inbox instead of the spam folder or Promotions tab.
• Build a sender reputation that lasts
  Opens, replies, and "mark as important" prove to Gmail, Outlook, and the rest that you're a real sender. That reputation is what keeps you landing as you scale.
• Stay off blacklists
  Sudden volume spikes get new domains flagged and blacklisted. Warmup ramps your activity at a natural pace, so you build trust instead of tripping filters.
• Scale your sending without burning your domain
  Warming up first lets you raise daily volume safely. Send more, knowing your sender reputation can carry the load.
• Catch deliverability problems before they cost you
  Track inbox placement, spam rate, and blacklist status in real time, with alerts the moment something slips, so you fix it before the next campaign goes out.

Warmup Inbox Network

• 30,000+ real human inboxes
• Real opens, replies, and mark-as-not-spam
• 25+ providers, Gmail to Outlook

Deliverability, live

• Outlook spam rate climbed
  Caught and flagged 2h ago, ramp paused
  Back to healthy
  Resolved before your next send

Who it's for

• Marketers
  Lifecycle email that actually lives up to its name. Nurture sequences, product updates, announcement blasts — warm sending domains means your carefully-written copy actually reaches the people you wrote it for.

FAQ

How long does email warmup take?
You'll see the first improvements within 3 to 7 days, but a full ramp takes 14 to 21 days minimum. Spam filters look for a natural, gradual increase in activity, so rushing the process almost guarantees your domain gets burned. Once you're warmed up, keep warmup running alongside your campaigns to hold your reputation.

Can I send cold email campaigns while my inbox is warming up?
Yes, but proceed with caution. We recommend keeping your campaign volume low (e.g., under 20-50 emails per day) during the first few weeks. Let the warmup tool handle the majority of the traffic to establish a solid reputation baseline before you scale up.

Which email providers does Warmup Inbox support?
We support all major email service providers, including Google Workspace (Gmail), Microsoft 365 (Outlook/Exchange), Yahoo, and Zoho. Additionally, we support any custom email provider that allows connection via SMTP/IMAP.

Does email warmup prevent my emails from going to spam?
Yes, by building a positive sender reputation. Our network automatically opens, replies to, and rescues your emails from spam folders, training algorithms to trust your domain. However, to stay in the inbox, you still need to send good, personalized email copy.

How does email warmup work?
Email warmup works by gradually building your sender reputation through real engagement. You connect your inbox to the Warmup Inbox network, and 30,000+ real inboxes automatically exchange email with yours, opening, replying, and marking it as important. As your sending volume and positive signals rise at a natural pace, providers learn to trust you, so your campaigns land in the primary inbox instead of spam.