Allow Email Access from specific IP only, block everyone else

How do I disable email access to a specific email account (or cPanel primary domain emails) from every IP address in the world except for the one I whitelist? I check server logs and I see Temporary Block for 1800 seconds [LF_SMTPAUTH] lfd alerts because people from other parts of the world are trying to access my email account. --- Is there something similar I could do email account(s) for a primary domain on a cPanel account? Allow email account access to whitelisted IPs, block / deny everyone else? Normally, for a website, I could just add .htaccess file to a directory and copy / paste code below to very top: order deny,allow allow from 192.168.0.420 deny from all ErrorDocument 403 https://mywebsite.com