Practical guides on reducing bounces, improving inbox placement, and building better email practices.
Hard bounces and soft bounces are treated very differently by ESPs and mailbox providers. Getting the distinction wrong - and keeping the wrong type on your list - is one of the fastest ways to destroy your sender reputation.
A 25-step checklist for inbox placement in 2026, from DNS authentication and list verification to infrastructure, content and monitoring. Each step says what it proves and how to check it.
Most DMARC rollouts fail in one of two ways: stuck at p=none forever (no actual protection) or jumped to p=reject and blocked legitimate mail. This guide is the 90-day rollout we run for every customer - day-by-day actions, what to watch in aggregate reports, the 5 mistakes that derail it.
DNSBLs (DNS-based blocklists like Spamhaus and Barracuda) are real-time lists of IPs known to send spam. Mail servers check them on every incoming message and reject or filter accordingly. Being on even one major blacklist crushes deliverability. This guide covers how blacklists work, which actually matter, and the recovery playbook for each.
Microsoft's spam filters work differently from Gmail's. Outlook.com / Hotmail / Office 365 use SmartScreen + per-IP reputation via SNDS, and they're significantly more sensitive to bulk-sender patterns. This guide covers what actually moves Outlook deliverability, the diagnostic tools, and the 5 fixes that get mail back to the inbox.
Gmail handles roughly 30% of all consumer email globally. If your messages land in spam there, you're invisible to a third of your audience. This guide covers the 8 most common causes and the specific steps to fix each one.
Mailbox providers treat new sending domains with deep suspicion - for good reason, spammers use throwaway domains. Warming up means proving you're legitimate by sending small, high-engagement volume that grows steadily. Here's the exact playbook.
Email list hygiene is the ongoing practice of removing invalid, inactive, and dangerous addresses from your subscriber database. Here's a complete framework to keep your list clean.
Deep-dive guides on how email verification and inbox placement work
Email list hygiene guide: when to clean, how to remove disposable, catch-all, and spam trap
File prep, result fields, catch-all scoring, segmentation tiers, re-verify schedules, ROI math
Quarterly B2B email deliverability research
Real lessons from the first cohort
Every term defined: catch-all, greylisting, MX, SPF, DMARC, spam trap and more
How verification works - the 5-stage pipeline, accuracy, and use cases
Continue through related topics