send mail asp net c# in folder directory.

Question

Hi sir,
I generate employee payslip, id based on pdf file(Em1004.pdf) in a folder.
get employee id from pdf file name(employee id is split em1004) to find database employee e-mail id attached automatically send mail. same time to all 
Ex.
 
folder name - D:\Payslip
having 10 pdf file Em1001.pdf, emp1002.pdf, emp1003.pdf...etc

i, need employee id split only pdf name Em1001 it's empid.
ii, that employee id based on find database employee mail id, (Select Mailid from tbl_employee where empid='pdffilename')
iii. process: get mailid- [email protected] ,attached file- em1001.pdf, Send payslip every employee mail id each one pdf attached.
that is sir. please help me