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Writing on email verification

Short, sourced guides to keep your bounce rate low and your sender reputation safe.

An envelope with a green check mark, a generic cover for an article about emails that reach the inbox.

Deliverability

Why do my emails go to spam? 5 causes and fixes

Emails go to spam when authentication, bounces, complaints, consent or engagement fail. See the limits Google, Yahoo and SES publish and what to fix first.

· 7 min read

Generic cover illustration of an envelope with a green check mark

Deliverability

What is a good email bounce rate? Benchmarks and fixes

A good email bounce rate sits under 2% by sender guides, and Amazon SES reviews accounts at 5%. See the thresholds and how to lower your own rate.

· 7 min read

A plain cover illustration of an envelope with a green check mark

Deliverability

Gmail and Yahoo bulk sender requirements explained

Gmail and Yahoo set rules for bulk senders: SPF, DKIM, DMARC, one-click unsubscribe and a spam rate under 0.3%. See who counts as bulk and what to check.

· 7 min read

An envelope with a green check mark, standing for a clean email list

List hygiene

Email list cleaning checklist before your next campaign

Clean your email list before a cold email or newsletter campaign in 8 steps: remove duplicates, verify addresses, handle risky results, test a small batch.

· 7 min read

An envelope with a green check mark, drawn as a simple cover illustration for an article about email lists

List hygiene

Why buying an email list burns your domain

A bought email list brings bounces, spam complaints and provider limits. See the numbers Amazon SES, Google and Yahoo publish, and what to do instead.

· 7 min read

An illustration of an envelope with a green check mark on it

List hygiene

How fast do email lists decay? Facts and a clean-up routine

ZeroBounce's report says at least 22.71% of an email list goes bad each year. See what old addresses cost you and how often to verify and clean a list.

· 7 min read

Illustration of an email address passing through four verification layers in order

Guide

How email verification works, layer by layer

How does email verification check an address without sending mail? Learn the syntax, DNS, list and SMTP layers and what each result really means.

· 3 min read

Illustration of a single mailbox that accepts every incoming envelope

Deliverability

What is a catch-all email? Reading an unknown result

A catch-all domain says yes to every address, so verification cannot see whether a mailbox exists. Learn how it is detected and when to mail these addresses.

· 2 min read

Clean your list before you send

Upload it, see every address's result and reason, download the clean part.

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