Thanks for the suggestion. I had a cursory look at them but their interface wasn't exactly clear for nonprofits. For example, I couldn't figure out how to get email going for the org. I'll give their support a shout and give them a second look.

We have used Zoho at our for-profit (free-tier - up to 25 people) with 5 GB Mailbox. We've had some issues when the HR tried to reach out to potential candidates and sent out some marketing emails. We were blocked and informed that it looks like spam. Do confirm with them before taking the plunge. Good luck!

How did you configure your free tier? We're being told that the org account is on a 30 day trial.

To give you some more info: We had signed up in 2016 timeframe when they had a more generous free tier. The one that I see now has 5 users [0]. Also, the startup is in India. Perhaps they're offering different tiers depending on the country?

[0] https://www.zoho.com/mail/zohomail-pricing.html