If you’re using email validation in your workflow, you already know the pain: bounces, false positives, or data that just doesn’t add up. Klemail promises to tidy up your lists and improve deliverability, but sometimes things go sideways. Maybe you’re staring at a pile of “unknown” results, or your supposedly “clean” list still gets flagged as spam. This isn’t a sales pitch—it’s a hands-on guide to fixing the stuff that actually trips people up.
Whether you’re a marketer, a dev, or just the person who drew the short straw in managing the email list, this article’s for you.
1. Understanding What Klemail Actually Checks (and What It Doesn’t)
Before you start troubleshooting, it helps to know what Klemail can and can’t do. The tool checks if an email address is:
- Properly formatted (e.g., no missing “@” signs)
- Associated with a real domain (does the domain exist and accept mail?)
- Likely to bounce (using SMTP checks and other methods)
- Disposable or role-based (like info@ or sales@)
But here’s what it doesn’t do:
- It can’t guarantee someone’s going to read your email—even if the address is valid.
- It can’t always spot “catch-all” domains, where every address looks valid even if it’s not.
- It won’t tell you if your content will land in spam.
Pro tip: Don’t expect miracles. Email validation reduces bounces, not rejection or deliverability issues.
2. “Unknown” or “Risky” Results: Why They Happen and What to Do
The Problem
You upload a list. Klemail spits out a bunch of “unknown” or “risky” verdicts. Now what? Should you keep these addresses or toss them?
Why This Happens
- Catch-all domains: Some mail servers accept all addresses, so Klemail can’t tell if the mailbox is real.
- Greylisting/temporary blocking: Some servers block validation requests to prevent spam.
- Server timeouts or slowdowns: If a mail server is sluggish or unreliable, Klemail might bail out.
What to Do
- Don’t panic: “Unknown” doesn’t always mean “bad.” It just means Klemail couldn’t get a straight answer.
- For catch-all domains: You’ll have to weigh the risk. These addresses might exist, or they might not.
- If you must email them: Send in small batches and monitor bounce rates. Don’t blast them all at once.
- Consider a second opinion: Run a sample through another validator. If two tools disagree, err on the side of caution.
Skip the temptation to email everyone. Bad bounces can hurt your sender reputation, especially at scale.
3. High Bounce Rates—Even After Validation
The Problem
You scrubbed your list, but you’re still getting bounces. What gives?
Possible Causes
- Old Data: Even a “valid” email might have gone dark since your last check.
- Spam traps: Validation tools can’t always spot dead addresses set up to catch spammers.
- Temporary Glitches: Sometimes, a mailbox is full or the server is down during validation, but active later (or vice versa).
What Works
- Validate close to send time: Don’t clean a list and let it gather dust for months. Email addresses go stale faster than you’d think.
- Remove hard bounces immediately: If you get a bounce, take that address out of your list right away.
- Don’t rely solely on validation: Use confirmed opt-in where you can. Yes, it’s more work, but it helps.
What to ignore: Don’t waste time chasing “zero bounce” promises. No tool can guarantee you’ll never get one.
4. Formatting Errors and Upload Failures
The Problem
You try to upload a list to Klemail, but it balks—maybe it’s the wrong format, or the parser chokes on weird characters.
Common Causes
- Bad CSV/Excel formatting: Extra commas, weird line breaks, or junk columns.
- Non-standard characters: Accented letters, emoji, or non-ASCII symbols can throw things off.
- Multiple columns: Klemail expects an email column; if your file is messy, it might not know where to look.
How to Fix It
- Clean your list: Open in Excel or Google Sheets. Make sure emails are in one clean column. Remove spaces, tabs, or hidden characters.
- Export as plain CSV: Avoid “.xls” or “.xlsx” if you can. CSV is less likely to cause headaches.
- Check for UTF-8 encoding: If you have international addresses, make sure your file is saved as UTF-8.
Pro tip: If Klemail can’t parse your file, try running it through a free online CSV validator first.
5. API Integration Headaches
The Problem
You’re integrating Klemail’s API into your app or website, but you’re getting weird errors, timeouts, or nothing back at all.
Usual Suspects
- Bad API keys: Double-check you’re using the right key for the right environment (test vs. live).
- Rate limits: Klemail’s API will throttle or block you if you send too many requests too fast.
- Malformed requests: Missing parameters, wrong endpoints, or bad data types.
- Firewall or network issues: Your server might be blocking outbound requests.
How to Troubleshoot
- Read the docs: Yes, it’s boring, but API docs usually spell out required parameters and error codes.
- Start with curl or Postman: Strip your request down to the basics. If that works, build up from there.
- Check for error messages: Klemail’s API returns codes and messages—don’t ignore them.
- Use logging: Log every request and response. It’ll save you hours when something breaks.
What doesn’t work: Guessing and hoping. If you keep getting 4xx or 5xx errors, stop and check the docs or support.
6. “Disposable” or “Role” Addresses: To Block or Not?
The Problem
Klemail flags some addresses as “disposable” (think temp mail) or “role-based” (support@, admin@, etc.). Should you nix these?
The Reality
- Disposable: These are almost always junk. Don’t bother emailing them unless you have a good reason.
- Role-based: Depends on your use case. For newsletters, avoid them—nobody checks “info@” for real content. But for B2B sales, sometimes these are legit leads.
What Works
- Segment them: Don’t delete immediately. Tag them and decide case-by-case.
- Test response rates: If you’re getting engagement from role addresses, keep them. If not, remove.
- Don’t stress about the occasional miss: No tool is perfect at spotting these, and sometimes people use role addresses as real inboxes.
Ignore the hype: Blocking all role-based addresses isn’t always smart. Use your judgment.
7. Deliverability Still Sucks—What Gives?
The Problem
Your list is squeaky clean, but Gmail still dumps you in spam. Frustrating, right?
Why Validation Alone Isn’t Enough
- Content matters: Spammy subject lines, bad links, or sketchy formatting will get you filtered.
- Sending reputation counts: If your domain/IP has a bad history, even perfect addresses won’t help.
- Authentication: Missing SPF, DKIM, or DMARC? You’re asking for trouble.
Practical Steps
- Check your sender score: Use tools like SenderScore.org to see if you’re on a blacklist.
- Authenticate your domain: Set up SPF, DKIM, and DMARC. It’s not optional anymore.
- Warm up new domains/IPs: Don’t send big blasts from a fresh domain right away.
What to ignore: Don’t think of Klemail as a “cure-all.” It’s a filter, not a silver bullet.
8. When All Else Fails: Getting Support (and What to Expect)
The Problem
You’ve tried everything, but you’re still stuck.
Real Talk
- Klemail’s support is responsive, but not magicians: They’ll help with platform issues, not your list hygiene.
- Be specific: When you contact support, include sample files, error messages, and what you’ve already tried. Vague emails get vague answers.
- Check their status page: Sometimes outages or known bugs are already listed there.
Pro tip: If your problem is business-critical, don’t hesitate to escalate. But don’t expect them to clean your list for you.
Wrapping Up: Keep It Simple, Iterate Often
Most email validation headaches come down to a handful of repeat offenders: bad data, over-expectations, or trying to brute-force a result. Use Klemail for what it’s good at—filtering obvious junk and flagging risk. Stay skeptical of “perfect” lists, keep your data fresh, and don’t be afraid to use a little common sense.
You’ll never eliminate every problem, but you can cut the noise and spend more time actually reaching real people. And that’s the point, isn’t it?