What is a catch-all email?
Why some domains accept every address, how verifiers detect them, and why they can't be confirmed.
GlossaryHard bounce vs soft bounce
Permanent vs temporary failures, the SMTP codes behind each, and what to do with them.
GlossaryRole-based email addresses
info@, sales@, support@: why shared inboxes are flagged risky, and when to email them anyway.
GlossarySpam traps
The three kinds of trap, how lists pick them up, and what verification can and can't do about them.
GlossaryVerification vs validation
Two words for overlapping things. What each usually means, and which checks actually stop bounces.
GlossaryEmail verification statuses
Deliverable, risky, undeliverable and unknown: every result and reason, and what to do with each.
GlossaryEmail bounce codes
A plain-English table of SMTP reply codes and enhanced status codes, and what to do about each.
GlossaryVerify an email without sending
The manual MX lookup and SMTP walkthrough, and why it often fails from a home connection.