The blacklist check is a tool that assesses a mail server's IP address by cross-referencing it with more than 100 DNS-based email blacklists, often referred to as Realtime blacklists, DNSBLs, or RBLs. When a mail server's IP address is blacklisted, there is a risk that some of the emails sent from that server may not reach their intended recipients.
These email blacklists serve as a widely used method for minimizing the impact of spam emails.
{"name":"Cotlas DNS Checker","ads":{"one":"","two":"","three":"","four":"","five":"","six":""},"socials":[],"colors":{"primary":"#0076d1","secondary":"#2fc10a","tertiary":"#d2ab3e"},"global":{"css":".navbar-brand img{\n height: 60px;\n}\n","js":"","header":"","footer":""},"cookie":{"enable":true,"text":"<p>By using this website you agree to our <a href=\"#\" target=\"_blank\">Cookie Policy<\/a><\/p>"},"font_family":"Poppins","text":{"above_map":"<h1><strong>Check DNS Propagation Easily<\/strong><\/h1><h2><br><\/h2><p>If you\u2019ve just updated your DNS records, changed your web hosting, or launched a fresh website, it\u2019s crucial to ensure your DNS records are updated worldwide. Cotlas DNS Checker is a free and reliable tool designed to help you verify DNS propagation across multiple servers around the globe. Simply enter your domain or hostname and get instant results showing DNS updates from various DNS servers. With this tool, you can quickly confirm if your DNS records have been fully propagated, making it easier to ensure everything is working perfectly.<\/p>","below_map":"<h2><strong>DNS Propagation Checker \u2013 How to Check DNS Updates Across the World?<\/strong><\/h2><p><br><\/p><p>Looking to check how your DNS changes are updating globally? With the Cotlas DNS Checker tool, it\u2019s quick and simple. Featuring over 100 global DNS servers, this tool makes checking DNS propagation a breeze. Unlike basic tools, it not only provides text-based results but also visually maps how your DNS records are updating across the world, making it easier to spot regional discrepancies or issues.<\/p><p>Whether you're troubleshooting or monitoring your DNS records, Cotlas DNS Checker is here to help. Follow these simple steps to perform a free DNS Propagation Test online:<\/p><ol><li><strong>Enter the Domain or Hostname<\/strong><\/li><li>Start by entering the domain name or hostname for which you want to check the propagation status.<\/li><li><strong>Choose the DNS Record to Check<\/strong><\/li><li>Select the specific DNS record you want to review using the dropdown menu. Here are the DNS record types you can look up with Cotlas DNS Checker:<\/li><\/ol><ul><li class=\"ql-indent-1\"><strong>A Record<\/strong>: Displays the IPv4 address of the hostname.<\/li><li class=\"ql-indent-1\"><strong>AAAA Record<\/strong>: Contains the IPv6 address of the hostname.<\/li><li class=\"ql-indent-1\"><strong>CNAME Record<\/strong>: Shows alias records, like redirecting <code>www.example.com<\/code> to <code>example.com<\/code>.<\/li><li class=\"ql-indent-1\"><strong>MX Record<\/strong>: Displays mail server details and priorities for email routing.<\/li><li class=\"ql-indent-1\"><strong>NS Record<\/strong>: Lists the authoritative nameservers for the domain.<\/li><li class=\"ql-indent-1\"><strong>PTR Record<\/strong>: Maps an IP address to a domain name (reverse IP lookup).<\/li><li class=\"ql-indent-1\"><strong>SRV Record<\/strong>: Specifies server configurations for services like VoIP or email.<\/li><li class=\"ql-indent-1\"><strong>SOA Record<\/strong>: Shows the \"start of authority,\" including important DNS zone details.<\/li><li class=\"ql-indent-1\"><strong>TXT Record<\/strong>: Provides text-based records, such as SPF, DKIM, or DMARC.<\/li><li class=\"ql-indent-1\"><strong>CAA Record<\/strong>: Highlights which certificate authorities are authorized to issue SSL certificates for the domain.<\/li><li class=\"ql-indent-1\"><strong>DS Record<\/strong>: Maintains a chain of trust between parent and child zones.<\/li><li class=\"ql-indent-1\"><strong>DNSKEY Record<\/strong>: Contains public signing keys like Zone Signing Key (ZSK) and Key Signing Key (KSK).<\/li><\/ul><p>With this comprehensive tool, you can easily monitor DNS propagation across different regions and manage your DNS records efficiently. Experience a smoother way to check DNS propagation with Cotlas DNS Checker!<\/p><p><br><\/p><h2><strong>Perform a Quick DNS Propagation Check<\/strong><\/h2><p>Once you\u2019ve entered all the details, click on the \u201cSearch\u201d button to run the DNS propagation test. Our tool will take just a few seconds to fetch and display the results, showing the status of your DNS records across various server locations worldwide.<\/p><p>Keep these pointers in mind while checking your DNS propagation status:<\/p><ul><li>\u2714\ufe0f A <strong>green tick<\/strong> means the DNS record has been successfully propagated.<\/li><li>\u274c A <strong>red cross<\/strong> indicates that the DNS record hasn\u2019t yet propagated to that server.<\/li><\/ul><p>To make it clearer:<\/p><ul><li>A green tick confirms that the requested DNS record is available on the DNS server.<\/li><li>A red cross might mean that the record hasn\u2019t been updated, or the value doesn\u2019t match what you\u2019ve set in the expected field.<\/li><\/ul><h3>With these clear indicators, you can quickly verify whether your DNS records are propagating as expected and identify any mismatches with ease.<\/h3><p><br><\/p><h2><strong>How to Easily Add a Custom DNS Server<\/strong><\/h2><p>Adding a custom DNS server to your settings is straightforward with our tool. Just click on the \u201c+\u201d button and provide the following details:<\/p><ol><li><strong>DNS Name<\/strong>: The name of the server.<\/li><li><strong>DNS IP<\/strong>: The IP address of the DNS server.<\/li><li><strong>DNS Provider<\/strong>: Identify the DNS provider for reference.<\/li><li><strong>DNS Map Latitude<\/strong>: Specify the server's geographical latitude.<\/li><li><strong>DNS Map Longitude<\/strong>: Specify the server's geographical longitude.<\/li><\/ol><p>Please note that the <strong>DNS Name<\/strong> and <strong>DNS IP Address<\/strong> are mandatory fields\u2014without them, the process won't work. If needed, you can also add the custom DNS server to the public DNS list with just a few clicks.<\/p><h2><strong>How to Add an Expected Value for IP Address<\/strong><\/h2><p>If your IP address has recently changed, you can specify the expected value of the new IP address using our tool's advanced controls. You can highlight this expected value in one of three ways:<\/p><ul><li>Using <strong>regular expressions<\/strong><\/li><li>Choosing numbers it <strong>contains<\/strong><\/li><li>Selecting an <strong>exact match<\/strong><\/li><\/ul><h2><strong>Additional Smart Search Capabilities<\/strong><\/h2><p>Head to the \u201cDNS Lists\u201d section to refine your DNS checks. You can monitor DNS propagation based on specific criteria such as:<\/p><ul><li><strong>IP Address<\/strong><\/li><li><strong>Continent<\/strong><\/li><li><strong>Country<\/strong><\/li><\/ul><p>Simply click the desired option (IP type, continent, or country) and proceed as instructed. For instance, if you want to check DNS propagation in <strong>Asia<\/strong>, select the continent, input your domain or hostname, and the tool will display the propagation status across Asia. This feature works seamlessly for <strong>IPv4, IPv6<\/strong>, and country-specific DNS lookups too.<\/p><h2><strong>Frequently Asked Questions (FAQ)<\/strong><\/h2><h3><strong>1. What is a Domain Name System (DNS)?<\/strong><\/h3><p>The Domain Name System (DNS) is a decentralized hierarchy that translates human-readable domain names into machine-readable IP addresses. Essentially, it's the internet's address book, helping devices locate each other online.<\/p><h3><strong>2. What is DNS Resolution?<\/strong><\/h3><p>DNS resolution is the process of converting domain names into their respective IP addresses. Four types of DNS servers collaborate to resolve queries:<\/p><ul><li><strong>Recursive DNS Server<\/strong>: Receives queries and fetches results from authoritative sources.<\/li><li><strong>Root DNS Servers<\/strong>: Direct requests to top-level domain (TLD) servers.<\/li><li><strong>TLD Servers<\/strong>: Handle requests for specific domains like <code>.com<\/code> or <code>.org<\/code>.<\/li><li><strong>Authoritative DNS Servers<\/strong>: Store and provide accurate DNS records for a domain.<\/li><\/ul><h2><strong>How Does the DNS Process Work?<\/strong><\/h2><p>Let\u2019s take an example: You type <code>https:\/\/xyz.com<\/code> into your browser. Here\u2019s what happens:<\/p><ol><li>The browser sends a query to a recursive DNS resolver, often provided by your ISP.<\/li><li>The resolver checks its cache for the domain\u2019s IP address. If cached, it returns the result.<\/li><li>If not, it queries root DNS servers for the TLD server of <code>.com<\/code>.<\/li><li>The root DNS server directs the resolver to the <code>.com<\/code> TLD server.<\/li><li>The TLD server refers the resolver to the domain\u2019s authoritative DNS server.<\/li><li>The authoritative server sends the requested IP address.<\/li><li>The resolver caches the response and provides it to your browser, enabling the page to load.<\/li><\/ol><h3>This efficient process ensures you can access websites with minimal delays.<\/h3><h2><br><\/h2><h2><strong>What is DNS Propagation?<\/strong><\/h2><p>DNS propagation refers to the time it takes for DNS changes to spread and update across the internet globally. When DNS records are updated, these changes can take up to <strong>48 hours<\/strong> to fully propagate worldwide. To check the progress, use our <strong>Global DNS Propagation Checker<\/strong> for a quick and free status report.<\/p><p><br><\/p><h2><strong>How Do DNS Records Propagate?<\/strong><\/h2><p>When DNS records are modified, the changes gradually update as ISPs (Internet Service Providers) refresh their DNS caches globally. During this transitional phase, not all users will experience the updated records immediately. Here\u2019s what happens:<\/p><ol><li>Visitors may still reach the old server\u2019s IP until their ISP updates its DNS cache.<\/li><li>Gradually, ISPs around the world fetch the new DNS information.<\/li><li>A majority of users will see the changes shortly after they\u2019re implemented.<\/li><\/ol><p>To examine your DNS details, you can perform a lookup for records like A, AAAA, or CNAME using our DNS lookup tool.<\/p><p><br><\/p><h2><strong>Why Does DNS Propagation Take Time?<\/strong><\/h2><p>DNS propagation delays stem from how caching works within ISPs. Here's the process:<\/p><ol><li>A user types a domain name into their browser.<\/li><li>The ISP first checks its <strong>local DNS cache<\/strong> for the relevant information.<\/li><li>If the data isn't cached or the TTL (Time to Live) for the old data expires, the ISP retrieves updated DNS information from the authoritative DNS server.<\/li><li>This process ensures faster lookup times in the future but can temporarily delay global updates.<\/li><\/ol><p>The variance in cache-refresh intervals among ISPs worldwide is why propagation isn't instantaneous.<\/p><h2><strong>Why is DNS Not Propagating?<\/strong><\/h2><p>If new DNS records don\u2019t reflect, it could be due to:<\/p><ul><li>ISPs caching the old DNS records until their TTL expires.<\/li><li>Issues in the DNS configuration or incorrect DNS record entries.<\/li><\/ul><p><strong>Solution:<\/strong><\/p><ul><li>Perform a DNS health check to verify your records comply with standards.<\/li><li>Flush your local DNS cache to avoid stale entries from your end.<\/li><\/ul><h2><strong>What Happens If a Domain Name Doesn\u2019t Exist?<\/strong><\/h2><p>When a DNS query is made for a non-existent domain, the DNS server returns an <strong>NXDomain error<\/strong> (Non-Existent Domain). This error indicates the queried domain name doesn\u2019t exist in the DNS records.<\/p><h2><strong>What Port Does DNS Use?<\/strong><\/h2><p>DNS primarily uses <strong>port 53<\/strong>, operating on both UDP and TCP.<\/p><ul><li><strong>UDP 53<\/strong>: Used for most DNS queries (maximum packet size: 512 bytes).<\/li><li><strong>TCP 53<\/strong>: Used for Zone Transfers or when query packets exceed 512 bytes, such as with DNSSEC queries.<\/li><\/ul><p>To check port availability, consider using an online port scanner.<\/p><h2><strong>What is DNS Failure?<\/strong><\/h2><p>A <strong>DNS failure<\/strong> occurs when the DNS server cannot resolve a domain name into an IP address. This failure may occur on a company\u2019s private network or on the broader internet, causing the requested domain to be inaccessible.<\/p><h2><strong>Which Are the Best DNS Servers?<\/strong><\/h2><p>Some of the top-performing global DNS servers include:<\/p><ul><li><strong>Google Public DNS<\/strong>: 8.8.8.8 \/ 8.8.4.4<\/li><li><strong>Cloudflare<\/strong>: 1.1.1.1 \/ 1.0.0.1<\/li><li><strong>OpenDNS<\/strong>: 208.67.222.222 \/ 208.67.220.220<\/li><li><strong>Quad9<\/strong>: 9.9.9.9<\/li><li><strong>Level3<\/strong>: 4.2.2.1 \/ 4.2.2.2<\/li><\/ul><p>These servers are known for reliability, speed, and global reach. Choose one that best suits your location and connectivity needs.<\/p>","footer":"<p class=\"ql-align-center\">Copyright 2024- DNS Propagation Checker by <a href=\"https:\/\/cotlas.net\" target=\"_blank\">Cotlas Web Solution<\/a><\/p>"},"find_btn":{"text":"Find","color":"#f56e00","text_color":"#000000"},"whois_btn":{"text":"Lookup","color":"#f56e00","text_color":"#000000"},"ip_btn":{"text":"Lookup","color":"#f56e00","text_color":"#000000"},"blacklist_btn":{"text":"Check","color":"#f56e00","text_color":"#000000"},"dmarc_btn":{"text":"Check","color":"#f56e00","text_color":"#000000"},"email_headers_btn":{"text":"Extract","color":"#f56e00","text_color":"#000000"},"default_dns":"A","enable_logs":true,"show_dark_mode":true,"enable_ad_block_detector":false,"ad_block_detector_filename":"adblock-detector.min.js","map_fail_reloader":true,"timeout":5,"blacklist":{"servers":["dyna.spamrats.com","all.s5h.net","b.barracudacentral.org","spam.spamrats.com","zen.spamhaus.org","dnsbl.dronebl.org","spam.rbl.blockedservers.com","rbl.interserver.net","spamsources.fabel.dk","bl.scientificspam.net","dnsbl.zapbl.net","bl.rbl.scrolloutf1.com","dnsbl.kempt.net","mail-abuse.com","bl.score.senderscore.com","exploit.mail.abusix.zone","new.spam.dnsbl.sorbs.net","block.dnsbl.sorbs.net","bl.spamcop.net","black.mail.abusix.zone","multi.surbl.org","escalations.dnsbl.sorbs.net","zombie.dnsbl.sorbs.net","dnsbl.tornevall.org","bl.nordspam.com","fnrbl.fast.net","talosintelligence.com","truncate.gbudb.net","0spam.fusionzero.com","bl.nosolicitado.org"]},"captcha":"recaptcha3","recaptcha2":{"site_key":"","secret_key":""},"recaptcha3":{"site_key":"6LeAjaUqAAAAAP_XIjzGe5Tc_0eXR-76sxF7fPHN","secret_key":"6LeAjaUqAAAAAKqIM2jnypCTMZFhtl40ugeYWgQi"},"hcaptcha":{"site_key":"","secret_key":""}}