Zoho Email Limits

Zoho Email Limits

Hello
I have to send a number of emails everyday to a number of clients. 

I am also using hosting at zoho.

Need to ask a couple of questions.

1. What is my number of Emails limit / Day?
2. What is the maximum number of recipients per email and per day?
3. What does it mean by " Too many emails in short interval of time"? and what is the calculation method?