Infrastructure
Email Address Validator
Check email syntax and whether its domain publishes MX records.
Examples
Validate a signup address format; check a company mail domain.
Common mistakes
MX records do not prove a mailbox exists; disposable addresses may pass.
Related tool: DMARC Checker →Tutorial on LearnWithIrfan: Mail servers on Ubuntu →Created by Muhammad Irfan Aslam, Senior Systems & Cloud Engineer.
Case study: How I fixed a server whose mail was going to spam →