Well, I'm no expert and I'm not in any position to say anything negative about Zoho Mail... but the free tier you mention seems to allow for one domain. So it l

Well, I'm no expert and I'm not in any position to say anything negative about Zoho Mail... but the free tier you mention seems to allow for one domain. So it likely won't work if you have, say, 5 active domains you want to receive and send email.