--- title: Guides — page 2 of 3 description: 60 Guides articles — Step-by-step guides to the free WatchFor tools: a real problem, a real run, how to read the result and what to do next. canonical: https://watchfor.io/blog/category/guides/page/2 --- [All posts](/blog) # Guides — page 2 Step-by-step guides to the free WatchFor tools: a real problem, a real run, how to read the result and what to do next. [All](/blog)[Monitoring](/blog/category/monitoring)[Networking](/blog/category/networking)[Performance](/blog/category/performance)[Security](/blog/category/security)[Reliability](/blog/category/reliability)[Email](/blog/category/email)[DevOps](/blog/category/devops)[Engineering](/blog/category/engineering)[Guides](/blog/category/guides) [All articles](/blog/all) 60 article s · page 2 of 3 [GuidesOct 04, 2026 ## DNS change not working? How to check DNS records with the DNS Lookup You edited a DNS record, saved it, and the site, mail or verification still behaves as before. To check DNS records properly, ask two places: the domain's authoritative nameserver, which shows what your DNS host really serves, and a public resolver, which shows what visitors get. Here's how to do both with the free DNS Lookup, how to read the answer, and the dig commands that show the TTLs.WatchFor Team6 min read](/blog/how-to-check-dns-records)[GuidesOct 04, 2026 ## Why are my emails going to spam? Check SPF, DKIM and DMARC with Email Health Mail from your domain lands in spam, and you want to rule out the usual cause first. To check email authentication, look at the three DNS records receivers use to trust your mail: SPF, DKIM and DMARC. Here's how to check them in one run with the free Email Health check, how to read the grade honestly, and what to fix for each red line.WatchFor Team6 min read](/blog/how-to-check-email-authentication)[GuidesOct 04, 2026 ## Why isn't my site HSTS preload-ready? How to check with the HSTS Checker You added Strict-Transport-Security, but the preload list refuses the domain, or a scanner still says the first visit isn't protected. To check HSTS, read the header on the bare domain's own HTTPS response, without following its redirect, and compare it with the preload rules. Here's how to do it with the free HSTS Checker, how to read max-age, includeSubDomains and preload, and the exact header the list expects.WatchFor Team6 min read](/blog/how-to-check-hsts)[GuidesOct 04, 2026 ## Deployed, but users still see the old page? How to check with the HTTP Headers checker You shipped a fix, it shows on your machine, and users still get the old version. The answer is in the response headers: Cache-Control, Age and the CDN's cache status say who served the page and how old it is. Here's how to check HTTP headers from outside your network with the free HTTP Headers checker, how to read the caching ones, and what to change when a stale copy is the problem.WatchFor Team6 min read](/blog/how-to-check-http-headers)[GuidesOct 04, 2026 ## What status code does my page return? How to check with the HTTP Status Checker Search Console says a page is "Not found (404)", yet it opens fine in your browser. The page you see and the status code the server sends are two separate things. Here's how to check the HTTP status code of any URL from outside your network with the free HTTP Status Checker, how to read the result, and how to fix a page that looks right but answers wrong.WatchFor Team6 min read](/blog/how-to-check-http-status-codes)[GuidesOct 04, 2026 ## I opened the port, so why can't I connect? How to check with the Port Checker You added the firewall rule, restarted the service, and the connection still times out. To check if a port is open, try a TCP connection to it from outside your network: open, refused and no answer at all each point to a different fix. Here's how to test any port in seconds with the free Port Checker, how to read the result and the server banner, and the nc commands that confirm it.WatchFor Team7 min read](/blog/how-to-check-if-a-port-is-open)[GuidesOct 04, 2026 ## Is my CDN actually caching? How to check with the Global CDN Checker You pay for a CDN, yet users in one region say the site is slow, and you can't tell whether the edge is serving from cache or going back to your origin every time. To check if your CDN is caching, request the same URL several times from many regions and read the cache status each edge reports. Here's how with the free Global CDN Checker, a real run across 20 locations, and the curl commands that show the same headers.WatchFor Team7 min read](/blog/how-to-check-if-your-cdn-is-caching)[GuidesOct 04, 2026 ## Is my IP blacklisted? How to check a mail server with the Blacklist Check Your mail bounces with "blocked using Spamhaus" or quietly lands in spam, and you suspect a blocklist. To check if your IP is blacklisted, look up your sending server's address on the DNS blocklists receivers use. Here's how to do it with the free Blacklist Check, what a clean, listed or refused answer means, and how to get delisted.WatchFor Team6 min read](/blog/how-to-check-if-your-ip-is-blacklisted)[GuidesOct 04, 2026 ## Why isn't our email arriving? How to check MX records with the MX Lookup Mail to your domain bounces, or part of it still lands at the old provider after a switch. To check MX records, look up the domain's MX set and confirm every host belongs to the provider you use now, with sensible priorities. Here's how to do it with the free MX Lookup, how to read priorities, and the dig commands that show TTLs.WatchFor Team6 min read](/blog/how-to-check-mx-records)[GuidesOct 04, 2026 ## Why does my SEO audit flag a redirect chain? How to check with the Redirect Checker An SEO crawler reports a redirect chain or a 302 on your homepage, and the browser just shows the final page. To check redirects, request the URL people actually type and follow every hop yourself: status code, Location header and timing for each. Here's how to do it with the free Redirect Checker, how to tell a harmless chain from a costly one, and the curl command that confirms it.WatchFor Team6 min read](/blog/how-to-check-redirects)[GuidesOct 04, 2026 ## Scanner says "missing security headers"? How to check with the Security Headers Checker A pentest report or a security questionnaire lists "missing HTTP security headers" and you need to know which ones, on which URL, and what to add. To check security headers, fetch the page the way a browser does and look for seven response headers. Here's how to do it with the free Security Headers Checker, what each missing header leaves open, and the config that adds them, even on a static host.WatchFor Team6 min read](/blog/how-to-check-security-headers)[GuidesOct 04, 2026 ## App can't find its server? How to check SRV records with the SRV Record Lookup Mail clients, SIP phones, XMPP chat, Minecraft and Active Directory find their servers through DNS SRV records, and when discovery fails the app just says it can't connect. To check an SRV record, look up the full service name (such as _submission._tcp.example.com) and read the target host, port, priority and weight. Here's how to do it with the free SRV Record Lookup, a real Gmail example, and the dig and nc commands that confirm the port answers.WatchFor Team6 min read](/blog/how-to-check-srv-records)[GuidesOct 04, 2026 ## Renewed the certificate but the old expiry still shows? How to check with the SSL Expiry Checker Let's Encrypt says the certificate renewed, yet browsers still show the old expiry date. Renewal writes a new file; only the server that loads it serves it, and every hostname can sit on a different server. Here's how to check SSL certificate expiry per hostname with the free SSL Expiry Checker, how to prove which certificate is live, and the openssl commands that compare it with the file on disk.WatchFor Team6 min read](/blog/how-to-check-ssl-certificate-expiry)[GuidesOct 04, 2026 ## Are TLS 1.0 and 1.1 really off? How to check with the TLS Version Checker An auditor, a PCI scan or a customer questionnaire asks you to prove that TLS 1.0 and 1.1 are disabled. To check which TLS versions a server accepts, offer it each version in turn and record which handshakes succeed. Here's how to do it with the free TLS Version Checker, how to read the protocol row, the openssl loop that produces evidence, and where the setting lives when an old version is still on.WatchFor Team6 min read](/blog/how-to-check-tls-versions)[GuidesOct 04, 2026 ## Domain verification failing? How to check TXT records with the TXT Record Lookup Google, Microsoft, Stripe or Atlassian asks you to add a TXT record, you add it, and Verify still fails. To check a TXT record, look up every TXT record on the exact name the service checks and confirm your token is there, complete and unquoted. Here's how to do it with the free TXT Record Lookup, what a busy real domain looks like, and the dig commands that show how long strings are split.WatchFor Team6 min read](/blog/how-to-check-txt-records)[GuidesOct 04, 2026 ## Is my website healthy? How to check it with the Smart Website Checker Someone asks whether the website is OK, or you inherit one and need to know what will break first. To check website health, look past "does the page load" at the things that fail on a date or fail silently: domain and certificate expiry, DNS, redirects, email authentication and blacklists. Here's how to get all of it in one scan with the free Smart Website Checker, and how to read a result that says A+ and still lists work to do.WatchFor Team7 min read](/blog/how-to-check-website-health)[GuidesOct 04, 2026 ## Is our domain about to expire? How to check with the Domain Expiry Checker A lapsed domain takes your website and your email down at once, and a renewal that silently failed is easy to miss. To check when a domain expires, read the expiration date the registry itself publishes over RDAP, not the date in a registrar email. Here's how to do it with the free Domain Expiry Checker, how to read the status flags that say whether a domain can still be saved, and the curl command that shows the same date.WatchFor Team6 min read](/blog/how-to-check-when-a-domain-expires)[GuidesOct 04, 2026 ## Rate limited until 1791068136? Convert it with the Timestamp Converter An API says you're rate limited until 1791068136, a log line starts with 1791065206319, and you need to know when that is in your own time. A Unix timestamp counts seconds since 1 January 1970 UTC; convert it and you get a date in UTC and in your timezone. Here's a real case from the GitHub API, how to spot a seconds-versus-milliseconds mix-up, and the date commands that do the same.WatchFor Team6 min read](/blog/how-to-convert-a-unix-timestamp)[GuidesOct 04, 2026 ## Is this JWT expired? Read exp and iat with the Epoch Converter Users get 401 "token expired" a few minutes after logging in. The answer is inside the token: its exp and iat claims are epoch times, seconds since 1970 UTC. Convert them and you know when the token was issued, when it dies, and whether the server or the token is wrong. Here's how with the free Epoch Converter, plus the jq one-liner that decodes a JWT locally.WatchFor Team5 min read](/blog/how-to-convert-epoch-time)[GuidesOct 04, 2026 ## New domain? How to create SPF and DMARC records with the SPF & DMARC Generator You're setting up email on a domain that sends from several services, and you need the two TXT records that make receivers trust it. To create SPF and DMARC records, list every service that sends as your domain in one SPF record, keep it under 10 DNS lookups, and start DMARC at p=none with a report address. Here's how with the free SPF & DMARC Generator, using a real three-provider setup.WatchFor Team6 min read](/blog/how-to-create-spf-and-dmarc-records) --- Canonical page: https://watchfor.io/blog/category/guides/page/2 · Site guide: https://watchfor.io/llms.txt