Hello Divyanshu,
really? :-) yes, MAI is another alerting infrastructure than CCMS, and CCMS is one of the data providers for MAI, MAI gets a part of its data from CCMS shared memory.
ST06 is not for alerting and sending e-mails, currently there is no alternative for ST06. The data in ST06 is required for remote SAP services, you have to configure it also in case if you are using MAI as the alerting infrastructure.
Regards,
Alwina