An email health check tests whether a domain's mail servers are properly configured to send and receive email. It scans the MX records for each mail exchanger and tests connectivity on standard SMTP ports.

SMTP (Simple Mail Transfer Protocol) is the standard protocol for sending email. This tool tests three ports: 25 (traditional SMTP, often blocked by ISPs), 587 (submission, the recommended port for authenticated email sending), and 465 (SMTPS, deprecated but still widely used).

STARTTLS upgrades a plain-text SMTP connection to an encrypted one. A server that supports STARTTLS protects your email content from interception during transit. This is a minimum requirement for modern email security.

MX records tell the internet which servers handle email for your domain. Missing or misconfigured MX records mean inbound email will bounce. Common issues include non-responsive servers, missing STARTTLS support, and slow response times that cause delivery delays.

Use this tool to verify your email infrastructure after changing DNS settings, diagnose delivery problems reported by recipients, or evaluate a mail provider's reliability before switching.