Direct answer
Mail delivery can sometimes fall back to an A or AAAA address where standards and server configuration permit, while an explicit null MX means no mail is accepted. Review the verifier's complete domain result.
More questions and answers
How do I remove emails from domains that no longer exist?
Group addresses by domain, check DNS and registration-related signals, and flag genuinely undeliverable domains. Keep the original list and any suppression history.
How do I remove Hotmail, Live and Outlook emails from a CSV?
Filter the exact Microsoft consumer domains you intend to exclude, including relevant regional variants. This is an audience selection rule, not an email-validity test.
How do I identify disposable domains without deleting Gmail?
Use a dedicated disposable-domain classification; consumer webmail providers are not the same as temporary inbox services. Review false positives before suppressing contacts.
What is a null MX record and should I remove the address?
A null MX indicates that the domain explicitly does not accept email. Treat addresses there as undeliverable unless the domain's configuration changes.
Can a domain accept email even if its website is down?
Yes. Website hosting and email delivery are separate services. Check mail DNS and server responses rather than assuming a failed website means a dead email address.
How do I sort my email list by provider?
Extract the domain after @, normalise it, then group Gmail, Microsoft, Yahoo and custom domains as needed. Provider categories alone do not tell you whether addresses are valid.