MX Record
A DNS record that specifies the mail server responsible for accepting email for a domain.
MX (Mail Exchanger) records are DNS entries that direct email to the correct mail server. When someone sends an email to user@example.com, the sending server looks up example.com's MX records to find which server to deliver to.
Example MX records:
``
example.com MX 10 aspmx.l.google.com
example.com MX 20 alt1.aspmx.l.google.com
``
The priority number (10, 20) determines which server to try first — lower numbers have higher priority.
What MX records reveal during verification:
- No MX records: The domain can't receive email — addresses are invalid
- Google MX records: Domain uses Google Workspace
- Microsoft MX records: Domain uses Microsoft 365
- Provider detection: Helps determine verification strategy
SendSure checks MX records at stage 2 of the 27-stage verification process. A missing or invalid MX record immediately classifies the email as invalid without needing further SMTP checks.
Related terms
SMTP Handshake
The process of connecting to a mail server to verify if a specific mailbox exists, without actually sending an email.
Email Verification
The process of confirming whether an email address is valid, deliverable, and belongs to a real person.
SPF (Sender Policy Framework)
A DNS record that specifies which mail servers are authorized to send email on behalf of your domain.
Related blog posts
Want to learn more?
Blog posts on verification and deliverability.