how to send mail with attachment using windows service.

I have created a application in  AXAPTA in which after TDS File approval Technical Dept. will click on "Submit" button. When he clicks on that button then the 'Status' field of my table PTDSFile changes to 'Closed'. Now we check that this  TDS File is for Old Product or new product in another database( database of my website). If it is for old product then it is uploaded on the server and the information is sent to "Design Dept. to update this product. If this TDS File is for new product TDS information with TDSFile as attachment is sent to Design dept.How we will do the above process using window service. Plesae guide me.