Email deliverability glossary: 40 terms every sender should know
Forty email deliverability terms defined in one or two sentences each: bounces, SPF, DKIM, DMARC, spam traps, greylisting, sender reputation, inbox placement and verification.
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Deliverability, explained.
Guides and research on email verification, bounce rates, catch-all domains, disposable addresses, list hygiene and sender reputation. Written by the people who run the engine.
12 posts tagged bounces
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@Sender reputation in 2026: what the Gmail and Yahoo bulk sender rules mean for you
Sender reputation explained: what Gmail and Yahoo measure, the February 2024 bulk sender rules one by one, how bounces and complaints feed it, and a 30-day recovery plan.
@How to reduce your email bounce rate (and why 2% is the line)
Keep hard bounces under 2% or mailbox providers start throttling you. Hard versus soft bounces, the main causes, a step by step cleanup plan and sunset policies.
@How to clean a Klaviyo list before your next flow
Clean a Klaviyo list the right way: export and verify, suppress undeliverable profiles, build a verified-deliverable segment, and keep sign-up forms clean with real-time checks.
@How to clean a Mailchimp audience (without losing good contacts)
Two safe ways to clean a Mailchimp audience: export, verify and re-import with update existing contacts, or connect Verifyre to tag and unsubscribe undeliverable addresses.
@Greylisting explained for marketers: why some mail is delayed
Greylisting is a mail server tactic that temporarily rejects unfamiliar senders with a 4xx code and accepts the retry. What it looks like in your reports, how long it lasts and what to do.
@The email list hygiene checklist for 2026
A ten-step email list hygiene checklist: verify at capture, clean before big sends, drop role and disposable addresses, sunset the unengaged and keep your bounce rate under 2%.
@How to clean a Brevo contact list before your next campaign
How to clean a Brevo contact list: connect with an API key, verify the list, write results to an attribute, move dead contacts to a suppression list or blocklist, and know when to re-run it.
@Email list decay: how fast do email lists go bad and what to do
Email lists typically lose 22% to 30% of their valid addresses every year. What drives decay, what it does to a 10,000-contact list, how to measure your own rate and how often to re-verify.
@How to clean a HubSpot contact list: verify, tag and suppress
A step-by-step guide to cleaning a HubSpot contact list: build the list, verify it through the integration, write the verdict to a custom property, then suppress and set undeliverable contacts to non-marketing.
@Hard bounce vs soft bounce: what the difference means for you
A hard bounce is a permanent rejection (5xx), a soft bounce is temporary (4xx). What causes each, how ESPs handle them, and when a soft bounce should be treated as hard.
@Email bounce rate benchmarks by industry in 2026: what is normal?
Typical email bounce rates by industry in 2026, how to calculate yours, where the 2% danger line sits, and how much list verification moves the number.
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