Dear XXX
Dear XXX
I'm writing to inform you that I can't go to work/school today because of illness. I am very sorry for any inconvenience that the short notice and my absence may cause you. According to the doctor, I should be fully recovered in two days. So, I should come back to work/school the day after tomorrow.
I'm writing to tell you that I can't go to work/school today because of illness. I'm sorry to inform you so late. My absence may cause you a lot of inconvenience in your work, and I apologize for that. The doctor said that my illness would be over in two days. So, I'm going to work/school the day after tomorrow.
Thank you for your patience and understanding.
Thank you for your patience and understanding.
salute
Thank you for your patience and understanding.
YYY
Sincere XXX