The Edit Subscription action in the Subscription Details node allows the user to change their subscription parameters during their paid cycle. Subscription parameters can be changed any time during the paid cycle.
The Parameters offered are Count of Active Jobs, Additional Database space and Additional Mass Mail credits. You will be charged for every additional purchase.
The Subscription Basis section displays the initial disk space provided for the first user i.e 5 GB and for every second user i.e 3 GB. Mass Mail credits are database based. For one database, per day the number of mass mails that can be sent are displayed as 250.
You can increase your subscription parameters according to your needs and you will be charged accordingly.