Check a domain the way inbox providers do
Enter a domain to see its SPF, DKIM, DMARC, MX and blocklist results in one go. It is free, needs no signup, and every check runs in your browser.
Checking your copy instead? Try the spam word checker
Six questions every email has to answer
Before an email reaches an inbox, the receiving server asks each of these. Each free tool answers one.
Is this server allowed to send?
SPF lists the servers that may send for your domain. Mail from anywhere else looks forged.
SPF checkerWas the email signed?
DKIM signs each email with a key published in your DNS, so the receiver can tell nothing changed on the way.
DKIM checkerWhat happens if the checks fail?
DMARC tells receivers what to do with email that fails SPF and DKIM. Google and Yahoo require it from bulk senders.
DMARC checkerIs the domain on a blocklist?
A listed domain, link or sending IP sends email to spam, or gets it refused outright.
Blacklist checkerCan replies get back?
MX records say where email for your domain is delivered. Without them, replies bounce.
MX lookupDoes the copy read like spam?
Filters read the words too. Trigger phrases, words in capitals and piles of links push an email toward spam.
Spam word checkerOne domain once, or every domain all day
These tools check one domain at the moment you ask. ArcWatch checks every domain and mailbox you send from, all day, and tells you when something changes.
- Records checked again after setup
- Listings flagged the same day
- Every email checked before it leaves
- How ArcWatch works
Questions about
the tools
Short answers about what the checks do.
Are these tools free?
Yes. There is no signup, and you can check as many domains as you like.
Does Arcinbox see the domains I check?
No. The checks run in your browser and look records up in public DNS, so nothing you enter is sent to Arcinbox.
Why does a blocklist say it could not check?
Some blocklists refuse lookups that come through public DNS resolvers. Could not check means the list did not answer, not that you are listed.
What should I fix first?
Start with SPF, DKIM and DMARC, since Google and Yahoo require them from bulk senders. Then clear any blocklist listing, and then look at your copy.
Found a problem? We will check the rest.
Book a deliverability audit and we will look at every domain and mailbox you send from.