Email Tools

Check the records that affect email delivery, sender authentication, and domain trust.

MX Lookup

Check the mail exchange records that receive email for a domain.

Find the SPF TXT record that controls which senders can mail for a domain.

Inspect a domain's DMARC policy for email authentication and reporting.

Look up a DKIM selector record and inspect the public key published for a domain.

Paste raw email headers to inspect routing hops, authentication results, and message metadata.

Build a clean SPF TXT record for domains that send email through apps and providers.

Create a DMARC TXT record for monitoring, quarantine, or reject policies.

Check whether an IPv4 address appears on common DNS blocklists used by mail receivers.

Run one domain check for MX, SPF, DMARC, DKIM, and sender IP blacklist signals.

Learn what the records mean, then use the tools to verify your domain.

Learn which email headers explain sender identity, delivery path, and authentication results.

A practical checklist for fixing SPF failures without breaking legitimate email senders.

Understand DKIM selectors and how they point receivers to the right public signing key.

Learn how p=none, quarantine, and reject affect domain protection and email delivery.

Common technical reasons legitimate email lands in spam and how to investigate them.

Copy practical SPF examples and learn how to combine common email providers into one safe TXT record.

Compare practical DMARC TXT records for monitoring, gradual enforcement, and strict domain protection.

A practical cleanup checklist for sender IPs that appear on DNS blocklists or suddenly land in spam.