> For the complete documentation index, see [llms.txt](https://doc.batch.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://doc.batch.com/guides-and-best-practices/email-deliverability/email-authentication-and-sending-structure/sending-subdomain-setup-and-troubleshooting/sending-subdomain-architecture.md). # Sending Subdomain Architecture ## Differentiating Domains & Subdomains An email subdomain is **a prefix** added to your **main domain name** that creates a distinct sending identity.
Email address anatomy
If your company domain is **`company.com`**, you might use subdomains like: * **news****.company.com**, for your newsletters and marketing communications. * **account****.company.com**, for your service related communications. * Etc ## Why Use Separate Subdomains Instead of a Root Domain? Most mailbox providers track the reputation of **each subdomain separately**. Think of it like having different phone numbers for different departments in your company—each builds its own reputation based on how it's used. We strongly recommend using **dedicated subdomains for different email types**—particularly separating transactional emails (e.g. password resets, receipts, account notifications) from marketing emails (e.g. newsletters, promotional campaigns). Here is how a typical email setup looks like:
{% hint style="info" %} Know more on the ideal sending structure and subdomains in our dedicated article: [Sending Infrastructure Best Practices](/guides-and-best-practices/email-deliverability/email-authentication-and-sending-structure/sending-infrastructure-best-practices.md) {% endhint %} --- # 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: ``` GET https://doc.batch.com/guides-and-best-practices/email-deliverability/email-authentication-and-sending-structure/sending-subdomain-setup-and-troubleshooting/sending-subdomain-architecture.md?ask= ``` The question should be specific, self-contained, and written in natural language. 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.