Mass email: only 20 mails allowed per day ( instead of 250)

Mass email: only 20 mails allowed per day ( instead of 250)

Today I have upgraded to the paid Standard version of Zoho CRM. I am now experiencing that there is a daily limit of 20 (mass) mails per days, see enclosed screenshot. I have been informed that it should be 250 per day. Can you clarify?