Email Verification
The process of confirming whether an email address is valid, deliverable, and belongs to a real person.
Email verification is a multi-step process that checks whether an email address is valid and can receive messages. Modern verification engines like SendSure use up to 27 stages including syntax validation, DNS lookups, SMTP handshakes, and AI-powered catch-all resolution.
Verification typically classifies emails as valid, invalid, risky, accept-all, or unknown. The goal is to remove undeliverable addresses before sending campaigns to protect sender reputation and improve deliverability rates.
Common verification stages include:
- Syntax check: Validates the email format against RFC 5322
- DNS/MX lookup: Confirms the domain has mail exchange records
- SMTP handshake: Connects to the mail server to confirm the mailbox exists
- Catch-all detection: Identifies domains that accept all emails
- Disposable email check: Flags temporary/throwaway addresses
- Role account detection: Detects generic addresses like info@ or support@
Related Terms
Bounce Rate
The percentage of emails that could not be delivered to the recipient's inbox.
SMTP Handshake
The process of connecting to a mail server to verify if a specific mailbox exists, without actually sending an email.
Catch-All (Accept-All)
A domain configured to accept emails sent to any address, regardless of whether the specific mailbox exists.
Sender Reputation
A score assigned by ISPs to your email sending domain/IP that determines whether your emails reach the inbox.
Related Blog Posts
Want to learn more?
Read our in-depth blog posts on email verification and deliverability.