Thank you letters are critical to your job search success and should ALWAYS be sent after you interview for a position or speak with someone for career related advice.
Thank you notes should be sent within a day or two of the meeting or interview and via mail or e-mail. Hard-copy thank you notes can be either typed or handwritten. When writing thank you notes be sure to adhere to the following guidelines:
1) Be professional and thoughtful.
2) Help the recipient recall you and the position you are applying for or discussing.
3) Remind the employer about your qualifications. Consider highlighting a part of the conversation that especially interested or excited you.
4) Reaffirm you enthusiasm/interest in the position.
5) Follow up with any information that the interview or contact asked you to provide.