# MyDCHub > Free DNS, mail-authentication, TLS and network diagnostics, run from our own > resolvers and network in Dhaka, Bangladesh. Every tool is free, needs no > account, and has a JSON form for scripts and agents. Operated by XeonBD (https://www.xeonbd.com/). Queries resolve through resolvers we run ourselves rather than a third-party API, which is why a result can say where it was resolved from. ## Please use the JSON where there is JSON Three of these have a JSON form: the DNS propagation checker, the IP address lookup and the ASN lookup. Add `format=json` or send `Accept: application/json`. The JSON is the same data the page renders, with the findings as structured objects. Reading it instead of scraping the table is faster for you and gives your reader an answer we would stand behind. The rest answer HTML only. That is a gap rather than a policy, and the three above are the ones people asked for first. If you are building against this and want another one, say so. curl "https://www.mydchub.com/tools/dns-propagation?domain=example.com&type=TXT&format=json" Without a key this is free and rate limited by address. A key from a MyDCHub workspace lifts the per-address limit and counts against a daily allowance instead; send it as `Authorization: Bearer `. Responses carry `X-RateLimit-Remaining`, and over the allowance the answer is 429 with a reset at 00:00 UTC. See https://www.mydchub.com/docs. ## Tools ### Mail Tools - [SPF checker](https://www.mydchub.com/tools/spf): Check an SPF record, count its DNS lookups the way a receiver does, and find the mechanism that pushes it over the limit. - [DKIM checker](https://www.mydchub.com/tools/dkim): Look up a DKIM public key, read its real size out of the record, and tell a revoked key apart from a broken one. - [DMARC checker](https://www.mydchub.com/tools/dmarc): Read a DMARC record, and understand alignment, which is what most authentication problems actually turn out to be. - [MX lookup](https://www.mydchub.com/tools/mx): See where a domain's mail is actually delivered, and whether every host in the list resolves. - [Blacklist check](https://www.mydchub.com/tools/blacklist): Check a sending IP against the blocklists receivers actually consult. - [MTA-STS check](https://www.mydchub.com/tools/mta-sts): Check whether senders can be forced to use TLS when delivering to your domain, or can be silently downgraded. - [TLS-RPT check](https://www.mydchub.com/tools/tls-rpt): Check whether you would ever hear about a failed TLS delivery to your own mail servers. - [BIMI checker](https://www.mydchub.com/tools/bimi): Check a BIMI record, and whether the domain is in a state where it can actually work. - [Mail check](https://www.mydchub.com/tools/mailcheck): Send a real message and see the DKIM, SPF and DMARC result for it, not for what your records claim. ### DNS, SSL & Web - [SSL certificate checker](https://www.mydchub.com/tools/ssl): Check a site's certificate: expiry, whether it covers the name, and whether the chain is complete. - [DNS record lookup](https://www.mydchub.com/tools/dns): Every record a domain publishes, read into named columns: pick a type or take them all. - [DNS propagation checker](https://www.mydchub.com/tools/dns-propagation): Ask eighteen independent resolvers what they are holding, compare it against your own nameservers, and see how long the stale caches have left. - [Website speed test](https://www.mydchub.com/tools/speed): Measure a site from Dhaka or Miami, or all three at once: where the first byte goes, what the page weighs, and whether caching and compression are actually on. - [Reverse DNS check](https://www.mydchub.com/tools/reverse-dns): Check an IP address has a reverse name, and that the name resolves back to it. - [Site preview](https://www.mydchub.com/preview): Open a site on its new server before DNS moves, without editing hosts files. ### Domains & IPs - [Domain WHOIS lookup](https://www.mydchub.com/tools/whois): See who registered a domain, when it expires, where its DNS points, and whether it could be moved. - [IP address lookup](https://www.mydchub.com/tools/ip): Whose address this is: the network it belongs to, the operator announcing it, where it is registered, and who to write to about it. - [ASN lookup](https://www.mydchub.com/tools/asn): What a network announces, who carries it, and who buys transit from it. ## Other pages - [Pricing](https://www.mydchub.com/pricing): the paid plans, which add daily re-checking and alerts. The tools stay free. - [API and rate limits](https://www.mydchub.com/docs): the JSON form, keys, allowances and the 429. - [Status](https://www.mydchub.com/status): which of our resolvers is answering right now. - [Terms](https://www.mydchub.com/terms) and [Privacy](https://www.mydchub.com/privacy). ## What this site does not claim - Resolver locations. The propagation checker asks eighteen independent public resolvers, and they are anycast, so it does not draw a map or attach flags. What it measures is cache state, which is what DNS propagation actually is. - A service level. No plan carries one, nothing measures one, and the terms say so. - Geolocation precision. IP locations are estimates from a commercial database and are labelled as estimates. ## Reuse You may quote and cite these pages and call the JSON endpoints. A citation back to the page you used is appreciated and helps a reader check the answer themselves.