SecArsenalFree email domain validation tool checking DNS records, MX records, and mail server connectivity.
Platforms: Web · Last verified September 7, 2026
Free email domain validation tool checking DNS records, MX records, and mail server connectivity.
Only use this tool against systems you own or are explicitly authorized to test — see the disclaimer.
Best for: Email domain and mailbox verification. See the official site linked above for details.
SecArsenal is an independent, educational reference. It does not host, distribute, or provide exploit code — only descriptions of, and links to, publicly available third-party tools and operating systems.
By continuing, you acknowledge that you will only use the tools and techniques referenced on this site against systems, networks, or accounts you own or are explicitly authorized to test; that unauthorized access to computer systems may be illegal in your jurisdiction; and that all information is provided "as is," and that SecArsenal and its contributors assume no liability for how it is used.
These change how this site looks and behaves in your browser only. Nothing is sent anywhere — your choices are saved on this device.
Larger text
Increases text size across the site by ~20%.
Extra spacing
Looser line, letter, and paragraph spacing in article text.
High contrast
Brighter muted text and borders, no decorative textures.
Always underline links
Identifies links by more than color alone.
Strong focus outline
A thicker, higher-contrast outline for keyboard navigation.
Reduce motion
Turns off hover/focus transitions, regardless of OS settings.
These toggles are a first-party enhancement layered on top of markup we build to follow WCAG 2.2 Level AA guidance — they are not a substitute for accessible design, and we have not undergone a formal third-party compliance audit, so we don't claim full conformance. If you hit a real accessibility barrier anywhere on this site, please open an issue — we'd rather hear about it than have this panel stand in for fixing it.