Deliverability
Deliverability guides and product notes — no filler.
How to improve email deliverability
How to improve email deliverability: the seven levers that decide inbox vs spam — authentication, list hygiene, engagement, reputation, warmup, and more.
What are spam traps, and what can verification do about them?
Spam traps punish poor list hygiene, and no verifier can reliably detect one. The three trap types, why detection fails, and what actually protects you.
What is greylisting? Why honest verifiers say unknown
Greylisting makes mail servers say "try again later" to unfamiliar senders. What that does to email verification, and why honest tools return unknown.
Email bounce rate benchmarks: what's normal and what's not
The average email bounce rate is 2.33%, but normal varies by industry. Benchmarks by sector, how to calculate yours, and the fixes that actually lower it.
Why bounce rate is the metric mailbox providers actually watch
Hard bounces are the loudest reputation signal you send. Here's how providers read them, and the thresholds to stay under.