Berkeley Law advises sending a very brief thank-you email, whereas Virginia Tech advises sending a more detailed message by postal mail. These schools also provide samples of their styles. Career advice on Monster provides a sample similar to Virginia Tech, and Business News Daily provides a sample similar to Berkeley.
Virginia Tech and Monster suggest that thank-you letters should reiterate the strengths and the values of an applicant while also setting concerns that the employer may have had at ease. This style aims to improve an applicant's chances of being hired. Samples on these sites specifically reference the interview. The sample on Monster provides further information on educational background, including transcripts. Both end by offering any further information should the employer need it.
Berkeley agrees that thank-you messages are important but also run the risk of containing errors and hurting an applicant's chances. However, it advises sending a brief but formal email, although a traditional letter may still be used. The sample thanks the interviewer, references the interview and offers to provide more information. Business News Daily provides a similar but even briefer thank-you email; it thanks the employer, reiterates confidence in the position and offers to provide more information.