How to Check Email List Health and Sender Reputation

The Email secret 90% of Marketers miss: And It’s Not Just About Open Rates! I once helped a client discover that 30% of their “engaged” email list was full of dead ends. This was also affecting conversions and revenue. The culprit? Bounces. But not all bounces are created equal—and ignoring the difference could tank your sender reputation. Here’s the breakdown: 𝗦𝗼𝗳𝘁 𝗕𝗼𝘂𝗻𝗰𝗲𝘀 (𝗧𝗵𝗲 “𝗠𝗮𝘆𝗯𝗲” 𝗭𝗼𝗻𝗲): Temporary delivery failures. Causes: Full inboxes, server outages, or temporary blocklisting. Fix: Wait it out. If it happens 3 times in a short span, remove the address. 𝗛𝗮𝗿𝗱 𝗕𝗼𝘂𝗻𝗰𝗲𝘀 (𝗧𝗵𝗲 “𝗡𝗲𝘃𝗲𝗿” 𝗭𝗼𝗻𝗲): Permanent failures. Causes: Invalid addresses (typos like “gmial.com”), abandoned accounts, or catch-all inboxes that silently swallow (catch-all status) emails, even after you verified the list. Fix: Remove these immediately. Sending to them repeatedly flags you as spam. 𝗪𝗵𝘆 𝗧𝗵𝗶𝘀 𝗠𝗮𝘁𝘁𝗲𝗿𝘀: Clean lists = higher engagement = better ROI. ISPs track bounce rates to decide if you’re a spammer. Weekly list audits prevent deliverability disasters. 𝗪𝗵𝗮𝘁 𝘀𝗵𝗼𝘂𝗹𝗱 𝗯𝗲 𝘆𝗼𝘂𝗿 𝗮𝗰𝘁𝗶𝗼𝗻 𝗽𝗹𝗮𝗻? - Ask your email service provider how they handle bounces (do they auto-retry soft ones?). - Scrub hard bounces after the first failure. - Monitor soft bounces like a hawk—3 strikes, they’re out. - Test-drive solutions like EmailAddress.ai to pre-verify addresses and avoid guessing which emails are valid, catch-alls, or outright spam traps. As someone who’s spent 20+ years in B2B data industry, I’ve seen companies lose deals because their “perfect” email list wasn't perfect after all. Tools that separate real leads from dead ends turn your data into a revenue engine—not a liability. Seeing bounce issues as well? DM me for a chat! #EmailMarketing #B2BData #LeadGeneration #GTMStrategy

Your email deliverability is NOT just about great copy. The #1 mistake? Ignoring your sender reputation. Here's what happens: 1. Your list isn’t clean → bounces destroy your credibility. 2. You send too many emails too fast → ESPs flag you as spam. 3. You don’t warm up your domain → your emails land in junk folders. 4. Your emails are not relevant → low engagement signals ESPs to block you. Email is a trust game.  ESPs track every send, every open, and every reply. One mistake can put you on a blacklist overnight. At Woodpecker.co, we help businesses keep their emails landing in inboxes: ↳ Check your email authentication (SPF, DKIM, DMARC). ↳ Warm up your domain properly before outreach. ↳ Verify your contacts right before sending. ↳ Focus on engagement, not volume. Email deliverability is the foundation of outbound success. Miss it, and your best emails won’t even be seen. What’s your biggest challenge with email deliverability? PS If just 5% of your emails bounce, ESPs might start blocking ALL your emails.

How a client saved his 10,000+ email list from spoofing—and restored his deliverability The business owner: - Had a list of 10,000+ subscribers - Relied on email marketing for revenue - Hired someone on Fiverr to set up his email authentication Everything looked fine on the surface. His email service provider said he was “passing” authentication. So why did his open rates suddenly plummet? Turns out… A LOT of email service providers will say you’ve “passed” authentication when you only have p=none in your DMARC record. Technically, it passes. But it doesn’t protect you. And since he didn’t set up DMARC reporting, he had no way of knowing that ❌ Someone was trying to spoof his email ❌ He was getting hit with spam complaints ❌ His emails were quietly getting filtered out He reached out, worried he’d lose his audience. We stepped in and: ✔️ Diagnosed weak authentication ✔️ Set up DMARC reporting to monitor threats ✔️ Strengthened his setup to stop spoofing ✔️ Paused campaigns to rebuild his sender reputation ✔️ Relaunched with a healthy, engaged list Now, his emails land safely and open rates are climbing. Most people think “authentication is done” when their email service provider gives them a green check. But if you don’t have reporting set up… If your DMARC is set to p=none… If you never check your sender reputation… You could be losing deliverability without even realizing it. He caught the problem in time. But a lot of businesses don’t. Don’t assume your authentication is working just because it “passes.” Check your setup. Monitor your domain. And make sure your emails are actually landing where they should. Have you ever faced deliverability challenges? Drop a comment —I’d love to hear your experience.

Here's why bounce codes can be your secret email weapon: Most businesses: ✖️ See bounces as a problem to minimize ✖️ Ignore the valuable data in bounce codes ✖️ Miss critical insights about their sending reputation Smart businesses analyze bounce codes to: Identify domain reputation issues Spot sending issues quickly Fix list building problems before they tank performance Bounce codes help detect content red flags: Know when copy is too aggressive Understand what triggers spam filters Fix authentication issues fast Monitor IP health: Track shared IP abuse Identify throttling problems Optimize send volumes Real example: A client with 400k contacts was seeing a 5-6% bounce rate on major sends. Analysis showed throttling issues from sending too much, too fast. Simple fix: Spacing out sends. Result: Immediate deliverability boost. Want to improve your email performance? Start treating bounce codes as intelligence, not just errors to avoid. How often do you check your bounce codes?

If you aren't doing these things, you're eviscerating your email delivery rates... 1. Authenticate Your Emails: Implement SPF (Sender Policy Framework), DKIM (DomainKeys Identified Mail), and DMARC (Domain-based Message Authentication, Reporting, and Conformance) to authenticate your emails. Get to know Google Postmaster Tools. 2. Clean Your Email List Regularly: Remove inactive subscribers and invalid email addresses. A clean list reduces bounce rates and improves your sender reputation. 3. Segment Your Audience: Send targeted emails to specific segments of your audience. Personalization increases engagement, which signals to ISPs that your emails are valuable. 4. Craft Engaging Subject Lines: Create compelling and relevant subject lines to improve open rates. Avoid using spam trigger words like “free,” “buy now,” or “guarantee.” 5. Use a Reputable Email Service Provider (ESP): Choose an ESP with a good reputation for delivering emails and strong anti-spam measures. They can help ensure your emails are properly configured and compliant with regulations. 6. Optimize Email Content: Keep your emails concise, relevant, and visually appealing. Use a mix of text and images, and ensure your emails are mobile-friendly. Personalized video goes a long way. 7. Include a Clear Unsubscribe Option: Make it easy for recipients to unsubscribe if they no longer wish to receive your emails. This helps maintain a positive sender reputation and reduces spam complaints. 8. Monitor Your Email Metrics: Track key metrics like open rates, click-through rates, and bounce rates. Use this data to refine your strategy and improve future email campaigns. 9. Warm Up Your IP Address: If you’re starting with a new IP address, gradually increase your email sending volume. This helps build a positive sender reputation with ISPs. 10. Avoid Using URL Shorteners: URL shorteners can be associated with spam. Use full URLs or branded links to maintain trust and avoid triggering spam filters. 11. Ask for Whitelisting: Encourage your subscribers to add your email address to their contact list or whitelist. This ensures your emails land in their inboxes. 12. Check Your Email’s Spam Score: Use tools to analyze your email content for spammy elements before sending. This helps you identify and rectify potential issues that could land your email in the spam folder. By following these simple tricks, you can significantly improve your email delivery rates, ensuring your messages reach your audience effectively and boost your overall email marketing success. Feel free to share any additional tips or experiences in the comments!

I’ll never let a dirty email list near my SaaS again. A year ago, we were flying blind at Ajelix. Users signed up, but every week, more support tickets rolled in: “Didn’t get my confirmation.” “Can’t reset my password.” Our marketing emails were invisible. We kept tweaking subject lines and templates, changing ESPs, convinced that was the problem. The real issue? We had dozens of invalid or abandoned addresses in our list that no one questioned. Each bad email quietly chipped away at our sender reputation until even legitimate users couldn’t get through onboarding. At one point, our bounce rate spiked past 5% which is deadly for SaaS. We burned weeks blaming providers, migration tools, cold outreach tactics, anything but the real problem: a dirty list. Cleaning our lists before sending changed everything: - Bounce rate went from 5% to under 0.2% - Support tickets for missing emails dropped 70% - Open rate jumped from 20% to 67% Now, we validate every email with our API before it enters our system. It’s non-negotiable. It took nearly a year of losing users and budget for this lesson to stick. If you’re running SaaS or outbound, don’t make the same mistake. One bad import or unchecked signup can trash months of growth. What’s your process for keeping lists clean? Want to avoid the mess? You can run your list through Mailerio and start seeing clean results now: https://mailerio.com/ How are you handling this in your own process?

Too many B2B founders ignore this. (It quietly kills their outreach results.) Invalid emails are a silent revenue drain. Even 5–7% risky emails in your list can: Spike your bounce rates Destroy your sender reputation Wreck your deliverability Waste hours chasing ghosts I used to double verify lists - yes, even pay for a second one.. It worked. But it was a time and money sink. Then I switched to Bouncer. - It flags risky or toxic emails - Detects spam traps - Always verifies in real-time Since then, not only did my reply rates jump. But my domain reputation stays healthier for longer. And all my campaigns have around <1% bounce rate. So I can focus on better campaigns - without doubting my contact lists. Clean lists = more replies = more revenue

Your sender reputation is causing your emails to land in your customers' spam folder rather than their primary inbox. Sender reputation is what email providers (like Gmail, Outlook, etc) use to gauge whether or not they can trust what you're sending. ❌ Bad sender reputation = gonna land in spam ✅ Good sender reputation = gonna land in the inbox If your average open rates are <20%, this is an area you should explore Thankfully, there are a few things you can do to improve your sender reputation ---- #1 Clean your list Get rid of email addresses that have bounced and remove subscribers who haven't engaged with your emails in a long time. ---- #2 Send to smaller segments If your list has 200,000 subscribers, stop sending "blasts" to all 200k. Instead, send to smaller batches (like 10k at a time) with a more targeted message. This increases the likelihood they'll engage. ---- #3 Be relational Send emails "from" a real person, encourage customers to reply to your emails, and avoid aggressive and spammy sales tactics. As a side note, this is why we sometimes encourage distributors to use a secondary domain for their email marketing program. So for example, if their primary domain is "acmesupplier.com," we might use "acmesupplierstore.com" as a secondary domain. This protects the primary domain and ensures your work inbox and your website stay up and running. If you're struggling with deliverability and your emails are hitting the spam folder, shoot me a DM. Happy to see if we can help get you back on track.