If your domain manager is Yahoo, please follow the below steps.

1. Login to your Yahoo Domain Control Panel Refer to the Yahoo account-specific help page to get clear instructions on accessing your Yahoo Control Panel.
2. Select Domain from the toolbar at the top of the page.
3. Navigate to TXT records and click Add.
4. Enter the details for your TXT record. 
   • In the Host field, enter @ ​
   • In the TXT field, enter the TXT value generated in the Zoho Mail Admin Console
5. Click the Add button. You'll be returned to the TXT records page with your new record shown.
6. Now come back to mailadmin.zoho.com page and click 'Verify by TXT'.
7. If the DNS information is correctly propagated, the domain will be verified. You can proceed with the next steps to create user accounts. 

If your domain manager is Yahoo, please follow the below steps.

1. Login to your Yahoo Domain Control Panel Refer to the Yahoo account-specific help page to get clear instructions on accessing your Yahoo Control Panel.
2. Select Domain from the toolbar at the top of the page.
3. Navigate to A and CNAME Records and click Add.
4. Specify the Source as the code generated in your Zoho domain verification page (Example: zb12345678).​
5. In the Destination field, enter the value from the CNAME Value/ Points To/ Destination field of your Zoho Mail Admin Console.
6. Click Add to save the changes.

You have now added the CNAME successfully. You may have to wait for at least an hour for the changes to take effect in the DNS Servers. After an hour or two, log in to your Zoho Mail control panel and click Verify. Once your domain is verified, you can start adding users and creating mail accounts.

If your DNS is hosted with Yahoo, follow the below instructions to change the MX records of your domain and receive emails.

1. Login to your Yahoo Domain Control Panel Refer to the Yahoo account-specific help page to get clear instructions on accessing your Yahoo Control Panel.
2. Select Domain from the toolbar at the top of the page.
3. Navigate to MX Records and click Add.
4. Specify Host Name as mx.zoho.com and set Priority to 10.
5. And then, click Add.
6. Click Add to add another record and specify Host Name as mx2.zoho.com and the priority as 20.
7. Once done, click Add.
8. Click Add to add the third record and specify Host Name as mx3.zoho.com and the priority as 50.
9. Once done, click Add.

Ensure that only the above three records are listed for the MX records. Remove any other MX entries for the domain. You have now added the MX Records for your domain registered with Yahoo domain manager. You can check the MX records in Zoho's DNS MX Lookup tool by providing your domain name.