> For the complete documentation index, see [llms.txt](https://humanic.gitbook.io/humanic/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://humanic.gitbook.io/humanic/getting-started-with-humanic/domain-setup/sub-domains.md). # Sub-Domains Humanic sends emails using a domain you own. We recommend using subdomains (e.g., `updates.yourdomain.com`) to isolate your sending reputation and communicate your intent. In order to verify a domain, you must set two DNS entries: 1. [SPF](https://resend.com/docs/dashboard/domains/introduction#what-are-spf-records): list of IP addresses authorized to send email on behalf of your domain 2. [DKIM](https://resend.com/docs/dashboard/domains/introduction#what-are-dkim-records): public key used to verify email authenticity These two DNS entries grant Resend permission to send email on your behalf. Once SPF and DKIM verify, you can optionally add a DMARC record to build additional trust with mailbox providers. \ **What are SPF records** Sender Policy Framework (SPF) is an email authentication standard that allows you to list all the IP addresses that are authorized to send email on behalf of your domain.The SPF configuration is made of a TXT record that lists the IP addresses approved by the domain owner. It also includes a MX record that allows the recipient to send bounce and complaint feedback to your domain. \ **What are DKIM records** DomainKeys Identified Mail (DKIM) is an email security standard designed to make sure that an email that claims to have come from a specific domain was indeed authorized by the owner of that domain.The DKIM configuration is made of a TXT record that contains a public key that is used to verify the authenticity of the email. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://humanic.gitbook.io/humanic/getting-started-with-humanic/domain-setup/sub-domains.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.