Thank You Message for a Mentor—Samples of What to Write in Nov 30, 2014Thank You Message for a Mentor—Samples of What to Write in a Card. Updated on January 10, 2017. Oyewole Folarin. In the article you will find messages and sample thank-you letters for a mentor, for a mentor and teacher, and for a spiritual mentor. How to Contact Parents and Guardians During the School Year. by LearnFromMe 18.Reviews: 7Author: Oyewole Folarin Thank you letter to a mentor - LettersPro Thank You Letters. Thank-you letters are letters written to politely acknowledge a gift, service, compliment or an offer. Simply put, these are letters you write to express your gratitude and appreciation for someone's thoughtful actions.