Yes, you can manage your email volume by changing your monthly package.
In addition to the Pay-As-You-Go option, where you only pay for the emails you send, we offer a number of monthly packages for different volume levels. To view all the email broadcast packages, go here: http://blueutopia.com/pricing-emailbroadcast
If you wish to change to your package, you can do that easily by completing the form here: http://blueutopia.com/admin/index.php?module=193&child=197&form=change_emailpackage.
Please note that unfortunately we are not presently capable of automatically changing your account. As a result, when you upgrade your monthly package, the minimum term is for 3 months.