Let’s be real: If your cold emails hit the spam folder, you might as well be shouting into a void. This guide is for anyone using Woodpecker to send outreach campaigns who actually wants their emails to get read, not filtered out. No fluff, no magic tricks—just practical steps to help you avoid spam filters and actually reach people.
1. Start With a Clean Sending Setup
Before you blame spam filters for your problems, get your technical house in order.
- Use a reputable domain. Don’t send campaigns from a brand-new or sketchy-looking domain. Ideally, your domain should be “warmed up” (more on this below), have a real website, and not be on any blacklists.
- Set up proper authentication. This means SPF, DKIM, and DMARC records. If these sound like alphabet soup, just ask your IT person or domain provider—most have guides to set these up, and Woodpecker’s own docs can help. Without them, you’re basically waving a red flag for spam filters.
- Avoid free email services. Gmail, Yahoo, and Outlook addresses are for personal use, not outreach. Use your own domain.
Pro tip: Check your sending setup with a tool like mail-tester.com before you send a single campaign. If you score below 9/10, fix the issues first.
2. Warm Up Your Domain and Inbox
If you just registered your domain or haven’t sent much email from it, you’re on thin ice. Spam filters don’t trust newcomers.
- Start slow. For a new inbox, send a handful of emails per day—think 10-20, not hundreds.
- Engage in real conversations. Don’t just send; get replies. Ask friends or colleagues to reply and mark your emails as “not spam.”
- Use a warm-up tool if needed. Woodpecker offers automated warm-up. It’s better than nothing, but real interactions are even better.
Ignore anyone who says you can skip this if your list is “high quality.” It’s not about your list—it’s about your reputation as a sender.
3. Build (and Maintain) a Quality List
Spam filters love to see engagement. If your list is bad, none of the other steps will save you.
- Don’t buy lists. These are often full of dead or irrelevant addresses, which leads to bounces and spam complaints.
- Verify your contacts. Use a list cleaning tool before uploading to Woodpecker. A high bounce rate is a fast track to the spam folder.
- Go for relevance, not size. A smaller, well-targeted list beats a massive one that mostly ignores you.
Pro tip: Regularly remove unresponsive contacts. If someone hasn’t opened in months, they’re dead weight (and possibly hurting your deliverability).
4. Write Like a Human, Not a Marketer
Spam filters—and humans—are pretty good at sniffing out generic, salesy emails.
- Avoid spammy words. “Free,” “guaranteed,” “no obligation,” “click here”—these are classic triggers. Don’t write like a late-night infomercial.
- Keep it short and specific. Long, rambling messages raise red flags.
- Personalize, but don’t overdo it. Use Woodpecker’s personalization features to add names or company info, but make sure it sounds natural.
- Don’t use too many images or links. One or two is fine. More looks suspicious.
If your email reads like something you’d delete in a heartbeat, so will your prospects—and so might their spam filters.
5. Mind Your Sending Volume and Schedule
Blasting out hundreds of emails at once is a great way to get flagged.
- Ramp up slowly. If you’re new, start with 20-50 emails per day and increase gradually over a few weeks.
- Spread sends throughout the day. Woodpecker lets you randomize sending times. Use it. Natural patterns look less like spam.
- Watch your daily limits. Don’t exceed what’s typical for a human sender (even if Woodpecker technically allows it). For most, 100-200/day per inbox is plenty.
Ignore the temptation to “go big” out of the gate. Deliverability is a marathon, not a sprint.
6. Keep Your Content and Formatting Clean
You don’t need fancy HTML for outreach. In fact, it can hurt you.
- Stick to plain text or minimal formatting. Avoid heavy HTML, colored text, and weird fonts.
- Limit attachments. Attachments—especially large or executable files—are a huge spam flag. If you must send something, link to it instead.
- Check your signature. Overloaded signatures with logos, images, and social links can tip you into spam, too.
Pro tip: Send yourself a test email and check it in Gmail, Outlook, and mobile. If it looks weird, so will it for your prospects.
7. Monitor Deliverability (Don’t “Set and Forget”)
If you’re not tracking what happens after you hit Send, you’re flying blind.
- Check open and reply rates. Sudden drops can mean your emails are going to spam.
- Use seed accounts. Add a few test emails (Gmail, Outlook, etc.) to your campaigns to see where they land.
- Watch for bounces and complaints. High rates are a sign something’s wrong—bad list, bad content, or bad sending behavior.
Don’t obsess over open rates (they’re not 100% reliable), but big swings mean you need to investigate.
8. Handle Replies and Unsubscribes Promptly
Spam complaints are poison for your sender reputation.
- Respond quickly to real replies. The back-and-forth shows ISPs you’re legit.
- Remove unsubscribes fast. Woodpecker can handle this automatically, but check that it’s working.
- Don’t keep emailing people who ask to stop. This isn’t just best practice—it’s the law in many places.
A little respect goes a long way. Spamming people who’ve opted out is a sure way to get blacklisted.
9. Ignore the Myths (and the Overhyped “Hacks”)
Here’s what doesn’t work (or isn’t worth stressing over):
- Changing a few words to “trick” spam filters. Filters look at patterns, not just single words.
- Using “re:” or “fwd:” in your subject line. This is old-school and fooling no one.
- Sending from tons of different aliases. This just spreads your deliverability problems around.
- “Guaranteed inboxing” services. If someone promises this, run the other way.
Stick to the basics—they work.
10. Keep It Simple, Iterate, and Stay Curious
There’s no silver bullet. Deliverability is about doing the right things consistently: good setup, clean lists, human emails, and steady sending. The moment you try to outsmart the system, you’ll probably end up in a ditch.
Run small tests. Watch your results. Adjust as you go. And most importantly, resist the urge to overcomplicate things. The best campaigns are the ones that actually get seen—and that starts with just showing up in the inbox.