Run these lines on your command line one-by-one to ensure they are properly set. Make sure you replace the yourdomain.com, dkimKey and verifyCode variables before running.
now dns add yourdomain.com '@' TXT zoho-verification=verifyCode
now dns add yourdomain.com '@' MX mx.zoho.com 10
now dns add yourdomain.com '@' MX mx2.zoho.com 20
now dns add yourdomain.com '@' MX mx3.zoho.com 50
# SPF
now dns add yourdomain.com '@' TXT "v=spf1 include:zoho.com ~all"
# DKIM
now dns add yourdomain.com 'dkimKey._domainkey' TXT "v=DKIM1; k=rsa; p=DKIM_VALUE"
The changes do take a while to propogate, but this should be enough to get your new domain running on Zoho in no time.
possible to get a step by step guide, new to the platform