In particular, I remember an outage a year ago that was very ill-timed for me (as we were hyping our project) and they were a little slow to respond, it was literally a perfect storm as their offices in Chennai were hit by a Cyclone:

https://www.zoho.com/service-updates/blog/zoho-customer-supp...

they have also had more outages than GMail (but OTOH they have way better customer support, I was even reached by the CEO once!).

Outages list: https://twitter.com/nehemiahman/status/921378260583362560

I still think it's the best available option.