Daily i run some queries related to my application manually and mail those reports in the form of excel to my customers. Now i would like to automate this process.
I have got some idea that i have to use UTL_SMTP in my procedure and DBMS_Scheduler for this requirement. I am seeking for a help to complete this requirement by providing me some links or sample pl/sql code.
I think you are not obliged to use UTL_SMTP in this situation. Setting the security group id in your PL/SQL code allows you to use the easy to use APEX_MAIL package.
The following article explains how you set the security group id: http://riyazmsm.blogspot.be/2010/09/apexmail-package.html
Official APEX_MAIL documentation: http://docs.oracle.com/cd/E37097_01/doc/doc.42/e35127/apex_mail.htm