So zoho is quite happy to terminate their users with no recourse.
A couple of years ago my parents wanted to trial individual email for their very small business (just a few employees). Google had recently removed the free tier from Google Apps, and Zoho was the only company we could find that offered a similar service. I set it up and they used it for ~6 months with quite a few issues in that time, whether service outages or (more commonly) emails not being delivered due to Zoho's spam filter or the recipient's spam filter giving false positives. Customer support was near enough to useless.
So when we decided that it was worth upgrading to a paid plan we didn't stay with Zoho, due to the poor experience. If Zoho charged just a dollar or two for accounts it may help reduce all the problems they have with spammers abusing the service and the flow-on effects that has on their customer support.
Zoho customer support is worse than useless. They’ll happily call you back only to tell you that they can’t help because it’s someone else you need to speak to. It’s a real shame because the Zoho product line is vast and with more focus it could be brilliant. But every part of it has little issues that will never get fixed because it feels like there’s nobody within the frontline staff seems to want to really understand.
EDIT that all sounds more negative than I wanted it to. I think Zoho should charge people more and offer the service to go with it all while fixing the niggles that make their products feel flakey.