How to check how many emails monthly sent?

How to check how many emails monthly sent?

Hi i am new to zoho services , i am loving zoho sites , now using zoho campaigns . its proud for indians . made in india made for the world . keep going on...


On Dashboard its showing count of subscribers , But how can i check how many emails sent monthly , how many are left in my email plan. 

I am using free plan now . I sent only 4 campaigns in this month which consists of 300-500 subscribers . But when i am going to send new campaign its saying you have only 239 credits left . please upgrade plan..

In free plan how many emails we can send monthly??