Notebook of deep dives · 5 posts
Long-form pieces on SMTP verification, sender reputation, catch-all handling, pattern conventions, and the public data sources that make legitimate email discovery possible. Written for engineers, not marketers.
Walk through the SMTP RCPT TO handshake, why DNS lookups alone cannot verify an address, and how real-time verification differs from pattern-matching.
Read the full piece →How CT logs, npm metadata, and GitHub commits surface real work addresses. The compliance boundary. Why pattern learning + public data is the best approach.
How Postmaster Tools and SNDS thresholds work. Why under-verifying costs more than verification credits. The ROI of real verification.
How first@, first.last@, firstinitiallast@, and role-based addressing differ by company stage and industry. Why pattern learning matters.
Explain accept-all mail servers, why they inflate bounce rates, and how confidence-scored guesses differ from binary verified/unverified flags.