--- title: "Free DKIM Record Lookup & Auto-Discovery | AutoSPF" description: "Discover all DKIM records for any domain. Auto-scan 50+ common selectors to find SendGrid, Google Workspace, Microsoft 365, Mailchimp, and 100+ other providers - or look up a specific selector." image: "https://autospf.com/images/og-default.png" canonical: "https://autospf.com/tools/dkim-lookup/" --- Domain Selector (optional) Auto-Discover (49 selectors)Deep Scan (\~184 selectors) Scans common DKIM selectors via DNS-over-HTTPS to discover which email services sign messages for your domain. ## What is a DKIM Record? A DKIM (DomainKeys Identified Mail) record is a DNS entry that enables email senders to sign outgoing messages with a unique cryptographic signature. This signature acts as a digital fingerprint, allowing recipients to verify that an email genuinely originated from the claimed domain and hasn't been altered in transit. Think of it like receiving a letter sealed with a wax stamp - the stamp indicates the letter is authentic and hasn't been tampered with during its journey. As of 2023, approximately 80% of Fortune 500 companies use DKIM to secure their email communications. Authentication Flow ## How DKIM Authentication Works 1 ### Generate Key Pair A DKIM generator creates a private key (kept secret on your mail server) and a public key (published in your DNS). 2 ### Sign Outgoing Emails Your mail server uses the private key to create a unique encrypted signature for each outgoing email, added to the header. 3 ### Verify on Receipt The receiving server retrieves your public key from DNS and verifies the signature. If it matches, the email is trusted. Troubleshooting ## Common DKIM Issues ### Misconfigured DNS Records Typos or incorrect entries in TXT records are the most common cause. Double-check for missing quotation marks and proper formatting. ### Selector Mismatch Ensure the selector configured on your mail server matches exactly what's in your DNS record. Even minor discrepancies cause failures. ### Key Length Incompatibility Modern security standards recommend 2048-bit keys. If you're using an older system, verify it supports your chosen key length. ### DNS Propagation Delays After making DNS changes, allow several hours for propagation before testing. Changes don't take effect instantly across all nameservers. ## DKIM is just one piece of the puzzle AutoSPF handles SPF flattening so your DKIM and DMARC alignment stays intact. Start your free trial today. [Start Free Trial→](https://app.autospf.com/login)[View Plans & Pricing](/pricing/) Rated 5/5 on G2 · Trusted since 2018 ## What Our Customers Say ### "AutoSPF Flattens SPF Records Seamlessly & Keeps Changes Logged - I am quite pleased with the product" > It does what it promises to do, and does it very well. I appreciate that it keeps a log of changes made, which prevents many mistakes. A client's SPF record would have way too many lookups, but AutoSPF makes that problem go away. The length of the SPF record is typically not the issue; it's the amount of lookups in the record that are. AutoSPF "flattens" the record, automatically expanding the defined lookups to IP addresses or ranges. And it auto-updates the record when the un-flattened lookups change. PJ Peter J. President · Small-Business (50 or fewer emp.) ### "Helped us go beyond capacity" > AutoSPF did exactly as described, it helped us get past our 10 lookup limit. Afterwards, we hit another limit regarding overall capacity and when contacted, they quickly provided us with a new solution to eliminate capacity issues entirely going forward, so now we can add as many SPF records as needed. They also provided us with a personalized support video explaining their new method in its entirety using our instance as the example. VU Verified User Financial Services · Mid-Market (51-1000 emp.) [Read our reviews on G2 ](https://www.g2.com/products/autospf/reviews) ```json {"@context":"https://schema.org","@type":"Organization","@id":"https://www.wikidata.org/wiki/Q138897474","name":"AutoSPF","url":"https://autospf.com","logo":{"@type":"ImageObject","url":"https://autospf.com/images/autospf-logo.png"},"description":"Automatic SPF flattening and email authentication management. 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I appreciate that it keeps a log of changes made, which prevents many mistakes. A client's SPF record would have way too many lookups, but AutoSPF makes that problem go away. The length of the SPF record is typically not the issue; it's the amount of lookups in the record that are. AutoSPF \"flattens\" the record, automatically expanding the defined lookups to IP addresses or ranges. And it auto-updates the record when the un-flattened lookups change.","name":"AutoSPF Flattens SPF Records Seamlessly & Keeps Changes Logged - I am quite pleased with the product","publisher":{"@type":"Organization","name":"G2","url":"https://www.g2.com"}},{"@type":"Review","reviewRating":{"@type":"Rating","ratingValue":5,"bestRating":5},"author":{"@type":"Person","name":"Verified User","jobTitle":"Financial Services"},"datePublished":"2025-07-31","reviewBody":"AutoSPF did exactly as described, it helped us get past our 10 lookup limit. 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