--- title: "Domains" url: https://docs.catalyst.zoho.com/en/cloud-scale/help/mail/domains/ description: "Catalyst Mail enables you to send emails from your application by configuring your organization's email addresses of public or private domains, or the SMTP settings of any external email clients you prefer to use." last_updated: 2026-08-28T06:26:16Z service: Cloud Scale type: general --- # Domains If the sender email addresses you wish to use are not by public email providers such as Gmail or Outlook, and are hosted on a private domain such as your business's own domain through third-party email providers or hosting services, you will need to add and validate that domain in Catalyst. You can add the sender email addresses, after you validate the domain. Catalyst requires the authenticity of external domains and sub-domains to be verified. Domain validation is mandatory, as Catalyst needs to ensure that the domain an email is sent from is valid and trustworthy. Catalyst performs this validation of the domains and sub-domains you add, through their DNS configurations. This is done using the following email authentication and validation standards: * **DKIM**: [DKIM](https://www.zoho.com/mail/help/adminconsole/dkim-configuration.html) (DomainKeys Identified Mail) is an authentication method which uses encryption with public/private keys, to validate whether the emails are generated from the authorized servers. * **SPF**: [SPF](https://www.zoho.com/mail/help/adminconsole/spf-configuration.html) (Sender Policy Framework) is an email validation system which looks for spoofed or forged emails using a specific SPF record published for the domain with the details of the hosts that are permitted by the domain's administrators. This enables Catalyst to provide security for the applications you build with it. ### Add Your Own Domain To add an external domain in Catalyst: 1. Click the **Domain** tab in the _Mail_ component, then click **Add Domain**. ![catalyst_mail_domain](https://catalyst-docs-development.zohostratus.in/images/help/mail/catalyst_mail_domain.webp) 2. Enter the email address of the external domain. ![catalyst_mail_add_domain](https://catalyst-docs-development.zohostratus.in/images/help/mail/catalyst_mail_add_domain.webp) 3. Click **Create**. The domain is now added in the project and will be displayed in the Domain section. You can add and use multiple domains for sending emails from your application. You must now verify and authenticate the domain before you use it. ### Verify a Domain To verify an external domain: 1. Click **Verify Code** for the domain you want to verify in the _Domain_ section. ![catalyst_mail_domain_added](https://catalyst-docs-development.zohostratus.in/images/help/mail/catalyst_mail_domain_added.webp) This will automatically send an email to the email address containing a confirmation code. ![catalyst_mail_domain_verification_email](https://catalyst-docs-development.zohostratus.in/images/help/mail/catalyst_mail_domain_verification_email.webp) If you don't receive the email with the verification code, click **Resend Code** in the _Verify Code_ box. 2. Enter the verification code that was sent to the email address in the pop-up box in the console. ![catalyst_mail_domain_verification](https://catalyst-docs-development.zohostratus.in/images/help/mail/catalyst_mail_domain_verification.webp) 3. Click **Confirm**. If the verification code matches, the domain will be displayed as verified. ![catalyst_mail_domain_verified](https://catalyst-docs-development.zohostratus.in/images/help/mail/catalyst_mail_domain_verified.webp) > **Note:** You will not be able to verify public domain email addresses such as Gmail and Yahoo Mail, and hence not be able to send emails through Catalyst Mail using them. ### Authenticate your Domain You will also need to authenticate the external domain by validating its DKIM and SPF records. To do this, you must configure the DKIM and SPF record codes that are generated in Catalyst with the DNS settings of your domain's host. To authenticate an external domain: 1. Click **Validate** for the domain you wish to authenticate in the _Domain_ section. ![catalyst_mail_domain_auth_highlit](https://catalyst-docs-development.zohostratus.in/images/help/mail/catalyst_mail_domain_auth_highlit.webp) 2. Copy the **SPF** and the **DKIM** record codes shown in the pop-up window. ![catalyst_mail_domain_authenticate](https://catalyst-docs-development.zohostratus.in/images/help/mail/catalyst_mail_domain_authenticate.webp) 3. Navigate to the **DNS settings** of the domain's host and paste the SPF and DKIM record codes in the respective fields. This process will vary depending on the domain host you use. 4. After the record codes have been added and saved in the domain's host, click **Authenticate** in the _Authenticate Domain_ pop-up in the Catalyst console. After the SPF and DKIM record codes have been validated by Catalyst, your domain will be displayed as authenticated. ![catalyst_mail_domain_authenticated](https://catalyst-docs-development.zohostratus.in/images/help/mail/catalyst_mail_domain_authenticated.webp) Once the domain and the sender email address are verified, you will be able to send emails using the *Mail* component. ![catalyst_mail_domain_done](https://catalyst-docs-development.zohostratus.in/images/help/mail/catalyst_mail_domain_done.webp) You can also add and verify the email addresses of this domain to send emails from Catalyst in the same manner as described in [this section](https://docs.catalyst.zoho.com/en/cloud-scale/help/mail/email-configuration/#add-a-new-email-address).