Guides

Email verification & deliverability guides

Straight answers to the questions people ask before they clean a list: how verification actually works, what MX records and catch-all domains mean, and why mail bounces.

• How to verify an email address

  Step-by-step guide to verifying an email address for free: syntax, domain, MX records, disposable checks and SMTP verification, plus how to check a whole list.

• Email validation vs email verification

  Validation checks whether an address could receive mail; verification confirms the mailbox exists. Learn what each one catches, what it costs and when to use both.

• How to clean an email list

  A practical checklist for cleaning an email list: dedupe, fix typos, drop dead domains, remove disposables and role accounts, then verify the survivors before you send.

• Why do emails bounce?

  The real causes of hard and soft email bounces, what each bounce code means for your sender reputation, and how to cut your bounce rate before the next send.

• What is a catch-all email address?

  Catch-all domains accept mail for every address, so verification cannot confirm the mailbox. Learn how to detect them and how to email catch-all addresses safely.

• What is an MX record?

  MX records tell the internet which server receives a domain's email. Learn how to read them, what a null MX means, and how MX lookups reveal the mailbox provider.

• What is a disposable email address?

  Disposable, temporary and burner email addresses explained: why people use them, how they damage your list, and how to detect them before you send.