You don not have to send any emails for your CDSC A/C to be credited with shares that is automatic,when you buy shares they automatically are credited to your CDSC after T+4 your CDS Holdings will automatically be updated,the next morning as for your cash account,it acts just like any other account the cash need for purchases is debited and any proceeds from sales is also automatically credited.
Basically its a whole system that tries to minimize the use of emails and lets you control your own account
Make the money