Google WorkSpace - ₹125 per email id per month - like [email protected] - there‘s no longer a free tier at Google anymore. For one or two email addresses Google is fine.
For example, for two email ids, it would be ₹250 per month or ₹3,000 per year.
If you have a requirement of more than, say, 5 email ids, then we choose other providers like OpalStack.com where the number of email ids are unlimited - it‘s limited by the TOTAL storage space which is 50GB @$9.50 per month.
There is another new shiny email system called titan.email but there are extremely few providers for this, and if this gets traction, I‘ll recommend this to clients.