Are there any "hidden" steps for better email list hygiene? (My 7-stage pipeline)
Hey everyone,
I've been working on my own email infrastructure and realized that most of my deliverability headaches were actually just poor list hygiene. If you’re dumping unverified data into your sender, you’re basically sabotaging your own reputation before you even start.
I’ve built a 7-stage validation pipeline to clean my contacts, but I feel like I'm hitting a ceiling on accuracy. Here’s what I’m currently doing:
- Syntax & Format: Simple regex check.
- Global Deduplication: Making sure I'm not spamming the same person twice.
- Domain Typo Correction: Fixing common stuff like
gmal.com->gmail.com. - Disposable Check: Dropping temporary emails (mailinator, etc.).
- Role-based Detection: Filtering out
info@,admin@, etc. - MX Lookup: DNS check to see if the domain exists.
- SMTP RCPT TO Handshake: Doing a real-time handshake with the destination server.
My surprising discovery: I was genuinely surprised to find that even with major providers like Gmail or Outlook, if you configure your validator properly-specifically using rotating proxies and randomized EHLO spintax-you can actually get real 550 5.1.1 responses for dead accounts instead of just getting a generic 250 OK. It turns out they do provide accurate signals if you respect the protocol and don't look like a blind scanner.
My questions: I feel like I've covered the basics, but I’m looking for ways to get even better accuracy:
- Handling Catch-all domains: Since an SMTP check often returns
250 OKfor catch-alls, do you treat them as "Valid" (and risk the bounce) or "Risky" and exclude them? - Spam traps: Are there any clever ways to catch "seeded" spam traps that slip through these basic checks?
- Hidden checks: Are there any extra steps or "hidden" reputation checks I should add to my pipeline?
I’m curious to hear how you guys keep your lists pristine. Are there any extra steps I should add to my pipeline?