Update MX Records for Email delivery : Network Solutions 

1. Log in to your Network Solutions account.
2. From the Left Navigation menu, Click the + icon to launch Domain menu.
3. Click Manage Domain Names and Launch the Domain Details page for the domain you are trying to verify in Zoho.
4. For the option, ‘Change domain to point to’, Select the radio button Designated DNS.
5. Click the button ‘Apply Changes’.
6. Select Manage Advanced DNS Records from Advanced DNS Manager for the domain.
7. Locate the Mail Servers subdivision, and click Add/Edit.
8. In the Mail Server field, specify 'mx.zoho.com.' Make sure you add the period (.) at the end of the server name, specify the priority as 10.
9. Click Continue
10. Follow the same process to add another record with values, mx2.zoho.com. and priority as 20. 
11. Ensure that only the above 2 records are in the results to ensure correct email delivery. 

You have now added the MX Records for your domain registered with Network Solution.