There is a company offering me a job position as System Analyst with pretty higher salary than my current base, and after careful consideration I realize that this opportunity is too exciting for me to decline.
Honestly, It is very hard for me to resign from this company.
It has been a pleasure working with you and your team over the last three years (almost), I gained so many new experiences here. How ever to start a new challenge is good for my career future, so by this email I would like to ask for my resignation.