What causes DKIM key issues when DNS provider limits TXT record length?

Email marketer from SuperUser responds that some DNS providers have UI limitations that impose character limits even when the underlying DNS system supports longer records. They suggest checking the raw DNS records to confirm whether the entire key is actually being stored.

Email marketer from Email Geeks shares that sometimes those character limits are set up and enforced client side only, suggesting to try hacking the HTML or JavaScript validation.

Email marketer from StackExchange responds that whilst some hosts and registrars will offer minimum DNS TXT record limits, any host that is RFC compliant should conform to a minimum of 255 characters, but ideally, support up to 4096 characters per string.

Email marketer from Reddit suggests that if a DNS provider enforces a restrictive TXT record length limit, the simplest solution is often to migrate to a different DNS provider that supports longer records or provides better DKIM management tools.

Email marketer from EasyDMARC shares that incorrect or incomplete DKIM TXT records due to length limits will cause DKIM authentication to fail, leading to deliverability issues and potential spoofing problems.

Email marketer from GoDaddy Community explains that some providers suggest splitting long DKIM keys across multiple TXT records to bypass length limitations. They caution that this approach is not universally supported and might cause issues.

Email marketer from MXToolbox explains that exceeding TXT record limits can cause DNS lookup failures, and can affect email deliverability. Checking your DKIM record with external tools will help identify if this has occurred.

Email marketer from StackOverflow shares that if a DNS provider limits TXT record length, one workaround is to split the DKIM key into multiple TXT records. However, they caution that not all systems handle this correctly, so it's better to switch providers if possible.

Email marketer from cPanel Forum notes that while cPanel's interface might have limitations, the underlying DNS system often supports longer TXT records. They advise checking the actual zone file to verify the complete DKIM key.

Email marketer from Email Geeks suggests migrating to a provider that has a proper interface if the current one is pre-DKIM and CGI based.

Email marketer from Namecheap highlights that TXT record limitations with some DNS services may not adequately allow DKIM configuration, and recommends upgrading to a premium DNS service to allow longer record sets, or migration to another host.

Expert from Email Geeks explains that duplicate TXT entries will lead to an invalid DKIM key, and hence to no valid DKIM signatures.

Expert from Word to the Wise explains that because TXT records can be used to setup DMARC, problems can occur if there are too many of them, or they are not set up correctly. Advice is given to make sure any DNS record is not only correct but also conforms to any DNS record limits the provider might have.

Expert from Email Geeks emphasizes that relying on DNS having DNS hosted by a company competent at it is a very cheap investment in system stability.

Expert from Spam Resource explains that the Domain Name System (DNS) is a fundamental part of email and is useful to prevent malicious users from utilizing email by use of TXT records which can prove identity.

Expert from Email Geeks shares that you can put multiple strings into a single TXT record and they'll be concatenated, so you can fit up to 510-ish bytes in a single TXT record if the UI supports TXT records properly, but many of the low end web-based ones have weird arbitrary limitations.

Documentation from RFC Editor details the standard format for TXT records, indicating that they consist of one or more character strings, each with a maximum length of 255 octets. DNS servers should support this standard, and deviations can cause interoperability problems.

Documentation from Google explains the process of adding a DKIM record to your domain's DNS records. If the DNS provider limits the TXT record length, splitting the record might be necessary, but providers supporting longer records are preferred.

Documentation from Cloudflare explains that TXT records have a size limit, often 255 characters per string. If the DKIM record exceeds this limit, some DNS providers might truncate it, causing DKIM validation failures.

Documentation from DigitalOcean clarifies that if a single TXT record's data exceeds the 255-character limit, the data must be split into multiple strings within the same record. The DNS resolver will concatenate these strings. Incorrect implementation can lead to DKIM failures.