Question 1

What makes an email address valid?

Accepted Answer

A valid email has a proper format (user@domain.tld), the domain must exist and have MX (Mail Exchange) records configured to receive email. The format regex checks for the basic structure.

Question 2

What are disposable email addresses?

Accepted Answer

Disposable emails are temporary addresses that forward to spam or expire quickly. Services like Mailinator, Guerrilla Mail, and 10 Minute Mail provide throwaway inboxes often used for spam or signups you do not want to keep.

Question 3

What does "deliverability" mean?

Accepted Answer

This tool does a live check (via the Disify API) on whether the email domain resolves and can actually receive mail. A whitelisted or resolving domain is very likely deliverable; a non-resolving one will bounce.

Question 4

What are MX records?

Accepted Answer

MX (Mail Exchange) records are DNS entries that specify which mail servers accept email for a domain. Without MX records, an email address cannot receive mail even if the format is correct.