MxToolbox prints no price for its API and gives a free account 64 DNS requests a day, and 1Lookup returns every DNS record type of a name in one call for $0.010 when records are found.

Email delivery work. Its REST API runs the same checks as the site: DNS commands such as a, aaaa, mx, ptr, soa, spf and txt, SPF, DKIM, DMARC, BIMI, MTA-STS and TLS-RPT checks, blacklist lookups, network tests such as ping, trace and port checks, and a Monitor API to query, add and remove monitors.

No price for the API is printed on its API pages. Free accounts get DNS requests only: the rate-limit table lists 64 a day, reset at 12:00 am UTC, and no network requests. Paid plans have a quota per plan, and the product page has a Contact Us button. The prices elsewhere on the site, $129 and $399 a month, are for its Delivery Center monitoring plans, not the API. Checked October 2026.

2 credits per name with records, free when the name has no records. On the Starter plan ($99 a month for 20,000 credits) a name is about $0.010, which covers 10,000 DNS lookups a month and is $9.90 per 1,000. At the Enterprise end of the rate card it is about $0.004.

That cannot be said, because MxToolbox prints no API price to set beside it. What can be counted is requests: one MxToolbox request runs one command, so the A, AAAA, MX, SOA and TXT records of one domain are five DNS requests, and a free account's 64 a day cover 12 such domains. One 1Lookup call returns all eight types.

MxToolbox returns what each command asks for, and the commands it lists include a, aaaa, mx, ptr, soa, spf and txt but no cname, ns or caa command, with a dns command that runs a general health check. 1Lookup returns A, AAAA, CNAME, MX, NS, TXT, CAA and SOA together, and adds the mail provider, read from the MX hosts, and the DNS host, read from the name servers.

On everything around email delivery: SPF, DKIM, DMARC, BIMI, MTA-STS and TLS-RPT checks, blacklist lookups, a Monitor API and network tests on the same key, plus a free test endpoint that needs no key. 1Lookup's DNS Lookup returns the records and two labels, and does not grade them. For SPF, DKIM and DMARC, 1Lookup sells a separate Email Authentication Check.

When the domain does not exist, when it exists but has none of the eight record types, when an IP address has no reverse name, and when DNS does not answer in time, which returns a 503 with a Retry-After header. Each of those costs 0 credits. Only a name where something was found is billed.

Yes on both. MxToolbox has a ptr command for reverse DNS and an asn command, each its own request. On 1Lookup an IP address goes to the same endpoint as a domain and returns the names published for it, free when it has none. A CSV with a domain or IP column runs a whole list in one job.

If you troubleshoot mail delivery, check SPF, DKIM and DMARC, watch blacklists or keep monitors, MxToolbox is the fuller tool. If you want the DNS records of a name in one call with a price you can read, the mail provider and DNS host named, an IP address on the same endpoint and a bill of zero when nothing is found, 1Lookup's DNS Lookup bills 2 credits for every name with records.

Yes for email delivery work: nothing on this page matches its checks and monitors, and the free account and test endpoint let you try the commands. Ask for the API price before you plan around it, since it is not printed. If what you need is the records and where a domain's mail and DNS are hosted, compare the per-name price of 1Lookup.