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

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.

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.

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.

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.

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.

If you're only sending a few emails to people you know, no. But if you are sending hundreds of cold emails for lead generation, yes. Warmup builds up natural, human-like sending activity first — real messages exchanged with real inboxes — so providers (like Google) don't flag your sudden volume spikes as spam.

Email warmup is the process of gradually building trust with email providers. By slowly increasing your daily sending volume and generating automated positive engagement (opens and replies), you prove you aren't a spammer, ensuring your real campaigns land in the primary inbox instead of the spam folder.

Warmup Inbox is an email warmup service that builds your sender reputation automatically. You connect your inbox, and it exchanges natural-looking email with a network of real inboxes, gradually raising volume and engagement while monitoring your deliverability, spam placement, and blacklist status. Agencies, SDR teams, recruiters, and marketers use it to keep campaigns landing in the primary inbox, not spam.

Connect your email account to the Warmup Inbox network. Our system automatically sends and receives emails on your behalf, gradually increasing the volume and engagement (opens, replies, "mark as important") to prove to providers that you are a trustworthy sender.