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MXToolbox alternative for SPF, DKIM and DMARC: what DemiSignal does, and what it does not

What MXToolbox's lookups, Domain Health and Delivery Center do in its own words, and where DemiSignal's free check and paid monitoring replace them or do not.

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On this page
  1. What MXToolbox does, in its own words
  2. Where DemiSignal is a direct alternative
  3. Where it is not
  4. Monitoring: Delivery Center and DemiSignal plans
  5. Using both
  6. Sources

MXToolbox is a DNS and mail diagnostics toolbox: its home page (opens in a new tab) is an MX lookup with checks against 105 blacklists, and its Domain Health (opens in a new tab) product monitors mail servers, web servers and DNS. DemiSignal's free check covers the email-authentication part: SPF, DKIM, DMARC and MX in one pass, with a health score and what to fix first; the free tools add SPF and DMARC record generators, and paid plans from $19 a month add DMARC report monitoring. Blacklist checks and server monitoring are not among DemiSignal's four checks or three tools, so if that is what you use MXToolbox for, keep it. This page describes what MXToolbox does in its own words, where DemiSignal is a like-for-like alternative, where it is not, and how to run both.

What MXToolbox does, in its own words

MXToolbox's home page (opens in a new tab) is an MX lookup: it lists a domain's MX records in priority order, queried directly against the authoritative name server, with a Diagnostics link you can click that connects to the mail server, verifies reverse DNS, runs a simple open-relay check and measures response time, and it can check each MX record's IP against 105 DNS-based blacklists. Its SPF check (opens in a new tab) is a diagnostic tool that acts as an SPF record lookup and validator, and its DMARC check (opens in a new tab) parses the DMARC record for the queried domain, displays it, and runs a series of diagnostic checks against it. The blacklist check (opens in a new tab) tests a mail server IP address against over 100 DNS-based email blacklists.

Domain Health (opens in a new tab) runs hundreds of domain, email and network performance tests and returns a report that highlights the problem areas; the monitor it sells keeps tabs on your DNS configuration, your mail server, your mail servers' blacklist status and your web servers' SSL certificates. Free users are allowed one Domain Health check every 24 hours; upgrading gives unlimited checks and a Domain Health Monitor that performs over 30 tests on your domain every few minutes and alerts you to issues.

Delivery Center (opens in a new tab) is MXToolbox's DMARC product. Its page describes DMARC deployment with guidance all the way to a reject policy, verified sources with automatic detection of new and existing senders, SPF configuration monitoring with recommended changes, DKIM configuration checks, DMARC analytics on verified sources and inbox delivery, what it calls Adaptive Blacklist Monitoring of all your sending sources, and a 30-day satisfaction guarantee. You connect it by adding Delivery Center to your DMARC records.

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Where DemiSignal is a direct alternative

DemiSignal's free check reads SPF, DMARC, DKIM and MX in one pass, with no account needed, and only reads the public DNS records of the domain you enter: nothing is changed and no email is sent. It runs four checks. SPF: a missing record, a rule that lets anyone send (+all) or decides nothing (?all), a soft fail (~all), and a record close to or over the 10 DNS lookup limit. DMARC: a missing record, a policy of none, no reporting address, a policy that covers only part of your email, and subdomains left at none. DKIM: keys under commonly used selectors, flagging keys that are weak, revoked or of an unknown type. MX: a missing record, a single mail host with no backup, and a null MX. The findings combine into a health score out of 100, each check comes back as pass, warning, fail or error, and the results explain what each result means and what to fix first. SPF and DMARC details show straight away; the DKIM and MX details and a shareable link for whoever manages your DNS come after you add your email address.

The free tools go one step further than a lookup: they build what is missing. The SPF record generator turns the services that send your email into an SPF record with an estimate against the 10 DNS lookup limit, and the DMARC record generator builds a DMARC record one step at a time, starting by monitoring with a reporting address. Neither needs a signup, and nothing you enter is saved. See also our guide to SPF too many DNS lookups.

Where it is not

The DemiSignal check looks at four things: SPF, DMARC, DKIM and MX, and the free tools page lists three tools: the SPF, DKIM and DMARC check, the SPF record generator and the DMARC record generator. MXToolbox's blacklist check (opens in a new tab) tests a mail server IP against over 100 DNS-based blacklists, and its Domain Health (opens in a new tab) monitor keeps tabs on DNS configuration, mail server uptime, blacklist status and web server certificates; none of that is among DemiSignal's four checks or three tools. If you rely on MXToolbox for blacklist status or for diagnosing a server, nothing on this page replaces that.

Monitoring: Delivery Center and DemiSignal plans

Delivery Center (opens in a new tab) bundles DMARC analytics with sender verification, SPF and DKIM configuration monitoring and blacklist monitoring of your senders, with a 30-day satisfaction guarantee.

DemiSignal's pricing page publishes its plans. Starter is $19 a month, or $190 billed yearly, for one business domain with 100,000 DMARC-passing messages a month; Pro is $49 for five domains; Business is $99 for ten. Every paid plan includes DMARC report monitoring, scheduled DNS checks and change alerts. Only messages in accepted reports that pass DMARC through aligned SPF or DKIM count toward the allowance; failed or potentially spoofed traffic stays visible and does not use it. You connect reports by adding your private reporting address to your DMARC record, your policy stays the same, and the first report commonly arrives within 24 to 48 hours. You cancel in billing settings, and monitoring continues until the end of the paid period.

DemiSignal's home page gives the honest comparison: DNS checks tell you which settings are published, DMARC reports tell you how real sending traffic is being handled, and you need both to make an informed policy change. DemiSignal's paid plans do both, checking SPF, DKIM, DMARC and MX records and reading the reports; Delivery Center's blacklist monitoring of your senders is not among those plan features.

Using both

You do not have to choose. RFC 9989 (opens in a new tab), the DMARC standard, allows the record to list more than one reporting URI, separated by commas, and a report should be sent to each listed URI. So a DMARC record can carry the address Delivery Center (opens in a new tab) asks you to add and the private reporting address from a DemiSignal plan at the same time, and a report should be sent to each listed address. Our guide to DMARC reports reads one of those reports line by line.

Run the free check on your domain first. It shows whether SPF, DKIM, DMARC and MX are published and set up correctly, and what to fix first.

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Frequently asked questions

Is the DemiSignal check free like MXToolbox's lookups?

Yes. The one-off check needs no account or card, reads only the public DNS records of the domain you enter, and shows SPF and DMARC details straight away; the DKIM and MX details need an email address. The SPF and DMARC record generators are free too, with no signup.

Does DemiSignal check blacklists?

No. The check covers SPF, DMARC, DKIM and MX records and gives a health score. MXToolbox's blacklist check tests a mail server IP against over 100 DNS-based blacklists, and that is a job DemiSignal does not do.

Can I send DMARC reports to two services?

Yes. RFC 9989 allows a comma-separated list of reporting addresses in the DMARC record, and a report should be sent to each one, so you can keep Delivery Center or any other destination while adding DemiSignal's private reporting address.

Check your domain now

See the SPF, DKIM and DMARC records your domain publishes and what to fix first. Free, no account needed.

Create a free account