To add a custom domain email to your Gmail, sign in to your Gmail account, go to Settings, then Accounts and Import, and click Add a mail account under the “Check mail from other accounts” section. You’ll need to enter your domain email address and provide the POP3 server settings for incoming mail and the SMTP server settings for sending mail, all of which you can get from your hosting provider.
Here’s a step-by-step guide:

1. Log in to your Gmail account: Open your web browser and sign in to the Gmail account you want to receive your domain emails in.
2. Access Settings: In the top right corner, click the Settings gear icon, then select Settings.
3. Go to Accounts and Import: Select the Accounts and Import tab.
4. Start adding the account: Under the “Check mail from other accounts” section, click Add a mail account.
5. Enter your domain email: Type the full domain email address (e.g., yourname@yourdomain.com) into the pop-up window and click Next.
6. Select POP3 Import: Choose the option to “Import emails from my other account (POP3)” and click Next.
7. Enter your account details:

   a) Username: Your full domain email address.
   b) Password: The password for your domain email account.
   c) POP Server: Enter the incoming (POP) server address provided by your hosting company. (check details in inbox  first mail)
   d) Port: Select the correct port number for your server (e.g., 995 for SSL/TLS or 110 for non-SSL).

8. Configure sending (optional): If you want to send emails from your domain address through Gmail, click Yes when prompted and enter the outgoing (SMTP) server information and password.
9. Finalize the settings: Click Add Account to complete the process.
10. Verify ownership: Open your domain email inbox for a verification email from the Gmail team and paste the verification code into the pop-up in Gmail to confirm ownership of the account.