So, you’ve heard you need to “warm up” your email account before sending cold outreach or newsletters. But what does that actually mean—and is it really necessary? Short answer: yes, if you don’t want your emails to land in spam. The good news is, tools like Warmbox can automate most of the headache if you set them up right. This guide walks you through every single step, from signup to making sense of the results, and it’ll flag what matters (and what doesn’t) along the way.
This is for anyone new to email warmup—marketers, founders, even seasoned folks who just want it spelled out without the fluff.
Why bother with email warmup?
Let’s keep it real: if you’ve just registered a fresh domain or haven’t sent email from your account in a while, email providers (like Gmail or Outlook) are suspicious of you. Send a bunch of cold emails from day one and you’ll trip their spam filters. Warming up your account builds a history of “normal” email activity, so your campaigns are more likely to land in the inbox.
Does everyone need this?
- Yes: New domains, new sending accounts, or if you’ve had deliverability issues.
- Probably not: Old domains with a long, healthy sending history.
But there’s not much downside to warming up, other than a little time and cost.
Step 1: Sign up for Warmbox and get your bearings
First things first: head to Warmbox and sign up for an account. There’s usually a free trial, but you’ll probably want a paid plan if you’re warming up several inboxes.
What you’ll need before you start:
- Access to your email account (Gmail, Outlook, custom domain, etc.)
- Admin access to update DNS records (if you want the best results)
- 10 minutes and a coffee (optional, but recommended)
Once you’re in Warmbox, explore the dashboard. It’s designed to be simple, but don’t get lost in every chart just yet. We’ll get to what matters.
Step 2: Connect your email inbox
This is the step where most people get stuck—don’t worry, it’s not as bad as it sounds.
Here’s how it works:
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Pick your provider:
Warmbox supports Gmail, Outlook, Office365, and custom IMAP/SMTP accounts. Click “Add Inbox” and select yours. -
Authenticate:
- For Gmail/Outlook: You’ll log in via OAuth (the “Sign in with Google/Microsoft” popup). It’s secure and doesn’t give Warmbox your password.
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For custom domains: You’ll need your SMTP and IMAP server info (you can find this in your hosting/email provider’s docs).
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Set sending limits:
Warmbox will suggest default settings, like 30-40 warmup emails per day. Don’t crank this up to 200 thinking it’ll go faster. That’s a red flag for spam filters—slow and steady wins here.
Pro tip:
If you see “authentication failed” errors, double-check your password and whether you need an “app password” (some providers require this for third-party tools).
Step 3: Update your DNS records (if you haven’t already)
This is the unsexy but critical part. If you want your emails to land in the inbox, you need proper DNS records:
- SPF: Tells mailbox providers who’s allowed to send email from your domain.
- DKIM: Adds a digital signature to your emails. Looks technical, but just copy-paste.
- DMARC: Monitors and protects against spoofing.
Warmbox will usually point out if these are missing. It’ll give you the right DNS records to add—follow their step-by-step (your domain host’s support docs can help).
Don’t skip this.
No amount of warmup will save you if your DNS records are broken. Warmbox will flag issues, but it won’t fix them for you.
Step 4: Set up your warmup campaign
Now for the fun part.
- Choose your schedule:
- Let Warmbox automate it. The tool will gradually ramp up from a few emails a day to your target volume over a few weeks.
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Don’t try to speed it up. This isn’t gym cardio—slow is better.
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Pick the warmup network:
- Warmbox uses a network of real email accounts. Your inbox will send and receive emails from these accounts automatically.
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You don’t need to customize the content; the goal is just to mimic real, natural conversations. (If you see options to “customize messages,” don’t bother unless you’re bored.)
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Reply settings:
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Make sure replies are enabled. Warmbox will not only send but also reply to warmup emails, which is important. It tells providers your messages get real engagement.
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Start the campaign:
- Hit “Start” and watch the magic happen. Warmbox will show stats as your warmup runs.
What to ignore:
- Don’t obsess over the exact content of warmup emails. No one reads them.
- Don’t worry about “sending windows” unless you have a specific reason (e.g., you only want emails sent during U.S. business hours).
Step 5: Monitor deliverability—but don’t micromanage
You’ll see a lot of charts: inbox rates, spam rates, “positive signals.” Here’s what matters:
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Spam/junk folder rate:
If more than a handful end up in spam, pause and check your setup (especially DNS records). -
Inbox placement:
The higher, the better. But don’t panic if it’s not 100%—no one gets perfect results. -
Warmup volume:
You want to see the volume gradually increasing, not sudden jumps. If Warmbox suggests slowing down, listen.
What’s noise:
- “Engagement” scores and other vanity metrics. Providers care about real activity, not abstract scores.
Step 6: When is your account “warmed up”?
People overcomplicate this. Here’s a simple rule of thumb:
- New domains: 3-4 weeks of consistent warmup is plenty.
- Older domains: 1-2 weeks is often enough, unless you’ve had major issues.
You’re looking for: - Consistent inbox placement (90%+) - No DNS errors - No sudden spikes in spam placement
Once you’re there, gradually start your real campaigns. Don’t go from zero to 500 cold emails overnight. Ramp up over a few days.
Pro tips and honest takes
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Don’t run warmup forever.
Once your account is healthy, switch it off or reduce the volume. Otherwise, you’re just adding noise. -
Warming up isn’t a silver bullet.
If you send bad content or blast purchased lists, you’ll end up in spam anyway. Warmup helps, but you still need to send emails people actually want. -
Ignore “boost your reputation instantly” claims.
Deliverability is built over time. No tool can guarantee inbox placement. -
Check your real emails.
After warmup, send a handful of real emails to colleagues on Gmail/Outlook and ask if they land in primary inboxes. It’s the simplest test.
Wrapping up: Keep it simple, iterate as you go
That’s it. Setting up your first Warmbox campaign isn’t rocket science, and you don’t need to stress over the tiny details. Focus on a clean setup, let the tool do its thing, and watch for any red flags. If something’s not working, tweak your settings or slow down.
Don’t overthink it. Get started, see what works for your domain, and adjust from there. The real win is getting your emails in front of people—not chasing perfect “warmup scores.” Good luck!