Cold email is a minefield. You spend hours crafting the perfect outreach, hit send, and… crickets. Nine times out of ten, it’s not your pitch—it’s your emails landing in spam. If you’re tired of your cold emails getting ghosted by Gmail and Outlook, it’s time to warm up your inbox the right way.
This guide is for anyone serious about deliverability, whether you’re running sales, recruiting, or building your own thing. We’ll walk step by step through setting up automated email warm up campaigns with Mailwarm, the service built specifically for this job. You’ll get the no-nonsense version—what’s worth your time, what’s snake oil, and how to actually get your emails delivered.
Why Warming Up Your Email Matters
If you’re sending cold emails from a brand-new domain or inbox, ESPs (email service providers) don’t trust you yet. Blast out a bunch of messages and you’ll end up in spam or, worse, get your account flagged. Warming up means sending a slow, steady trickle of real-looking emails to build a good sender reputation.
What email warming does: - Sends and receives authentic-looking emails automatically - Gets your messages opened, replied to, and marked “not spam” - Gradually increases sending volume over days or weeks - Mimics real human conversations, not bulk blasts
What it can’t do:
It won’t fix a sketchy domain, bad content, or sloppy sending practices. Warming up is like stretching before a workout; it helps, but you still need good form.
Before You Start: What You Need
Don’t skip this. If you try to warm up an inbox that’s missing the basics, you’re just digging a deeper hole.
1. A fresh, properly configured inbox
- Domain age: Ideally, your domain isn’t brand new. Under a week old? Consider waiting—a “baby” domain is suspicious.
- DNS setup: Make sure SPF, DKIM, and DMARC records are set up. (If that sounds like gibberish, Google your provider’s setup guides. Seriously, this matters.)
- No blacklists: Check if your domain or IP is on any blacklists (use MXToolbox). If so, fix that first.
- No bulk sending yet: Don’t start cold outreach until the warm up is done.
2. Access to Mailwarm
- You’ll need an account with Mailwarm. It’s not free, but it’s purpose-built and saves a ton of time.
- Your login credentials for the email account you want to warm up.
Pro tip: If you’re using Google Workspace or Outlook, make sure IMAP/SMTP access is enabled for your account.
Step 1: Connect Your Inbox to Mailwarm
Mailwarm needs to plug into your email account to send and receive warm up emails automatically.
- Log in to Mailwarm.
- Go to “Add Inbox” or “Connect Account.”
- You’ll likely need to enter your email address and password, or use OAuth for Gmail/Outlook.
- Grant necessary permissions.
- Mailwarm asks to send, receive, and manage emails. This is required for full automation.
- Verify connection.
- Mailwarm will usually send a test email. If you see errors, check your credentials or IMAP/SMTP settings.
Heads up: If you use 2FA or app-specific passwords, set those up in advance.
Step 2: Set Up Your Warm Up Campaign
Here’s where most people overthink things. The goal is to start slow and look human—not to “game” the system.
Basic settings you should care about:
- Start volume: 10–15 emails per day is plenty for week one.
- Ramp up: Increase by 5–10 emails per day each week. Let Mailwarm handle the pace.
- Reply rate: Enable replies. This makes the activity look real, not robotic.
- Randomization: Make sure Mailwarm sends at random times, not all at once.
- Time zone: Set it to match your real location or where your audience is. Don’t send “work emails” at 3am.
What to ignore: - Custom templates or “fancy” content. Plain text emails work best for warming up. - Attachments or links. These are red flags for spam filters—skip them during warm up.
Step 3: Monitor Progress and Adjust
You don’t need to babysit Mailwarm, but don’t just set it and forget it, either.
What to watch:
- Daily report: Mailwarm gives you open/reply stats and spam folder checks.
- Spam rate: If more than 5% of warm up emails land in spam, pause and check your DNS records or sending history.
- Blacklist alerts: Some plans include blacklist monitoring. Pay attention and act fast if you get flagged.
If things go wrong: - Too many spam placements? Double-check your SPF/DKIM/DMARC. Sometimes, you need to slow down the ramp-up. - No opens or replies? Mailwarm’s network may be slow, or your inbox isn’t properly connected.
Don’t obsess: Some spam is normal, especially early on. Trends matter more than any single day.
Step 4: Finish the Warm Up Before Outreach
Most people want to start blasting cold emails after a few days. Don’t. Give it at least 2–4 weeks, especially for brand-new inboxes.
What’s “done” look like? - 100–150 emails per day getting sent/received with no spikes in spam rates - Consistent opens and replies from Mailwarm’s network - No blacklist hits
Once you’re there, you can taper off the warm up and start sending real outreach. It’s smart to keep a low level of warm up running in the background, especially if you plan to send high volumes.
Step 5: Keep Your Deliverability Healthy
Warming up is just the start. Here’s how to not screw it up moving forward:
- Don’t send huge blasts. Ramp up your cold outreach volume gradually—think 20–30% more per week, not overnight jumps.
- Avoid spammy content. Too many links, weird formatting, or “buy now” language will tank your reputation fast.
- Mix in real replies. Actually respond to people, even if it’s just “thanks.”
- Monitor your sender score. Use tools like Google Postmaster or MXToolbox to keep tabs on health.
- Rotate inboxes if needed. For big campaigns, spread sending across multiple warmed up inboxes.
What Works, What Doesn’t, and What’s Just Hype
What actually helps:
- Gradual, automated warm up using a tool like Mailwarm
- Good DNS records and a reputable domain
- Realistic, human-like email activity
What’s a waste of time:
- Paying for “guaranteed inbox” hacks or shady black hat services
- Over-engineering your warm up with fancy templates or attachments
- Trying to brute-force volume before your inbox is ready
What you might hear (but should ignore):
- “You don’t need warm up if your domain is old.” Not true—any new inbox can get flagged.
- “Just use a different sending tool.” Won’t matter if your reputation is shot.
Keep It Simple and Iterate
Warming up your inbox isn’t glamorous, but it’s the foundation for any real cold email strategy. Use Mailwarm to automate the boring stuff, keep an eye on your stats, and don’t rush it. Most importantly, focus on steady, healthy sending. You’ll save yourself a lot of headaches—and get more replies from real humans, not just the spam folder.
Now go set it up. Your future self will thank you.