Respected Sir/Madam,
I, __________ (name) working as ___________ (designation) in your reputed company and my employee ID number is __________ (employee ID number).
Courteously, I am writing this email with the utmost respect in order to bring into your kind consideration that I was provided with one day of sick leave for __/__/_____ (date) but unfortunately, I am not still feeling well and therefore, I request you to kindly provide me sick leave for another day i.e. __/__/_____ (date).
I ensure that I will be joining from __/__/_____ (date) onwards. Kindly acknowledge the same.
Thanking you,
Sincerely,
__________ (Name),
__________ (Employee ID),
__________ (Contact details)