How To Write A Absent Letter To Professor . Lastname, please accept this letter as documentation of my absence from march 2 through march 6, 2020, due to sickness. This is the most necessary reason to write the excuse letter. Absent Excuse Letter for Not Attending Class from www.scribd.com Headline the letter with the name of the school. The 1st paragraph should include your name, grade and class you are in. The reader should be able to concede your reason for being absent.