Dear [Applicant]:
It was a pleasure meeting you yesterday and having the opportunity to discuss your education, career goals, and potential contributions to [Company]. I appreciate your candid replies and feel that since your objectives are to work within the [describe] industry, that you continue to seek a position with a firm that would enable you to gain experience in this area.
Unfortunately, our business does not afford you an opportunity to gain this experience. I am certain that you will find a position which suits you soon and I believe that you have a great deal to contribute. Please accept my best wishes for your future.
OR
Thank you for your recent application to join our company as a sales assistant. While we do not have an opening in your area at this time, we will certainly keep your application on file. Should a position become available in the future, we shall inform you and arrange a convenient time for testing.
OR
Thank you for your recent application for employment with [Company]. We regret to inform you that there are no openings at this time. While we know this is disappointing news, we would like to retain your application in our files for future openings. Thank you again for your interest in working with [Company].