> For the complete documentation index, see [llms.txt](https://docs.emaillabs.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.emaillabs.io/en/email/sender-security/senders-authorization/restricting-authorization-to-specific-smtps.md).

# Restricting Authorization to Specific SMTPs

<figure><img src="/files/EjdAhwZtutPMi0TOJJf1" alt=""><figcaption></figcaption></figure>

To limit sending from the domain to specific SMTP servers, access the authorized domain Preview, expand the Status section, and select the SMTP servers authorized to send messages from the domain.

<figure><img src="/files/Q4v4KqPd4dWwlD3EmCpS" alt=""><figcaption></figcaption></figure>