It is with considerable reluctance that I am sending this letter. Although my time with (the company) has been on the whole satisfying and productive, for quite a while now I have become less and less content with the situation. Decisions have been made that I disagree with, some of which have adversely affected me personally. The direction of the company, the department in which I work, and the new targets and the methods of accomplishing them are making it increasingly difficult for me to feel that I'm contributing sufficiently.
Therefore, it is with regret that I ask you to accept this as my resignation from (the company) effective Friday, July 15.