Question 1

What does this email lookup tool check?

Accepted Answer

It checks publicly available DNS records (MX, SPF, DMARC) and WHOIS/RDAP domain data. It identifies the mail provider, validates the email format, detects disposable domains, shows domain age and registrar, and produces a deliverability score. It does not send email or probe SMTP servers.

Question 2

What is a deliverability score?

Accepted Answer

The deliverability score (0–100) reflects how well the email domain is configured to send and receive mail. It rewards having MX records, a strict SPF policy, a DMARC policy set to quarantine or reject, and a domain age over one year.

Question 3

What is SPF?

Accepted Answer

Sender Policy Framework (SPF) is a DNS TXT record that lists which mail servers are allowed to send email on behalf of a domain. A strict "-all" policy tells receivers to reject mail from unlisted servers.

Question 4

What is DMARC?

Accepted Answer

DMARC (Domain-based Message Authentication, Reporting and Conformance) builds on SPF and DKIM to tell receiving servers what to do with email that fails authentication — reject it, quarantine it, or just monitor.

Question 5

Does this tool verify that the email inbox exists?

Accepted Answer

No. This tool only looks up public DNS records and domain registration data. It does not connect to mail servers or send email, so it cannot confirm whether a specific inbox exists.

Question 6

What is a disposable email?

Accepted Answer

Disposable (throwaway) email providers like Mailinator or Guerrilla Mail create temporary inboxes anyone can access. This tool detects addresses from known disposable providers.

Question 7

What is a plus-tag in an email address?

Accepted Answer

Many providers (Gmail, Fastmail, ProtonMail) support sub-addressing: user+tag@domain.com delivers to the same inbox as user@domain.com. Tags are useful for filtering or tracking where you gave your address.

Email Address Lookup