Email domain health check
SPF, DMARC, MX and blocklists for any domain in one report. Each problem comes with what it breaks and the record that fixes it. The link in the address bar opens the same report.
How to read the result
Each section gets one of four marks. Pass: nothing to do. Needs attention: it works, but something is weak or close to a limit. Problem: receivers will fail this check, fix it first. Could not check: DNS or a blocklist did not answer; it is not the same as a missing record.
Fix in this order: a missing or broken SPF record (several records, or more than 10 lookups, both fail every message), then a DMARC record (start with p=none and a report address), then blocklist entries.
The blocklist section checks the domain's own mail servers, the ones in its MX records. If you send through Resend, SES or Postmark, mail leaves from their servers, which they monitor; those do not show up here.
Questions
- What does an email domain health check look at?
- The DNS records receivers read before they trust your mail: SPF (which servers may send for the domain), DMARC (what to do with mail that fails), MX (who receives replies and bounces), and whether the domain or its mail servers are on public blocklists.
- My domain passes. Will my emails land in the inbox?
- Passing means receivers can authenticate the domain, which Gmail and Yahoo require. Inbox placement also depends on DKIM (set up with your sending provider), your sending history, complaint rate and content. This check covers the DNS part.
- Why is a check marked “Could not check”?
- The DNS server or the blocklist did not answer in time, or refused the query. That says nothing about your records either way, so it is not shown as missing. Run the check again in a minute.
- Do you store the domains I check?
- Not when you only run a check: it runs live over DNS, the answer is kept in memory for five minutes so a shared link opens fast, and nothing is written anywhere. If you ask for weekly monitoring, we keep your email, the domain and the last statuses (not the records) until you stop it.
More free tools
No sign-up, nothing stored. All tools.
SPF record checker
Parses the SPF record, counts its DNS lookups against the limit of 10 and says how to fix what breaks it.
DMARC checker
Reads the DMARC policy, report addresses and alignment, and says what the policy actually does to spoofed mail.
DKIM checker
Reads a DKIM key by selector, or searches the common ones, and checks its type and length.
MX lookup
The mail servers of a domain, their addresses and who hosts the mailboxes.
Blocklist checker
A domain and its mail servers against public DNS blocklists.
Email provider lookup
Which mailbox provider and which sending services a domain uses.
Email address verifier
Format, mail servers, throwaway domains, role addresses and typos for one address.
Bulk email checker
Up to 100 addresses from a pasted list or a CSV, with a CSV of the results. Nothing stored.
Disposable email checker
Whether an address or domain belongs to a throwaway-mail service.
Email HTML preview
Paste email HTML, see it on desktop and phone with images on or off, and what breaks in Gmail and Outlook.
Merge tag tester
A template with {{tags}} and JSON data in, the email out, with every tag that would reach the recipient unfilled.
Subject line checker
How a subject and preheader look in iPhone Mail and Gmail, where phones cut them, and what reads like a pitch.