You have a monthly allowance of email credits which allows you to send email messages to your customers and 1 email equals 1 email credit.
Depending on the package that you have signed up depends on the amount of credits that you have. Click here to find out how many email credits you are entitled to. If however, you want to add more email credits on to your account you can as well.
Simply go to 'My Account' and select 'Payment & Credits'.
Then click on the red 'Purchase Credits' button to add more credits to your account.
You can also decide what type of credits to but. Either 'SMS Credits' or 'Email Credits'. Simply select the relevant choice and click on the blue 'Purchase' button to complete the purchase.