Respected Sir/ Madam,
This is to inform you that my name is __________ (name) and I have been working in your school for the last _________ (years).
I am writing this email to notify you that I have to attend a marriage function at _______ (location). In this regard, I would like to take leave from __/__/_____(date) to __/__/_____(date) and I request you to kindly grant me the leave. As you know that I barely take any leave but due to this unavoidable situation I have to avail my leave.
I hope that you will approve my request for leave and do the needful. If you have any questions or concerns, please do not hesitate to contact me at any time.
___________ (Employee ID)
___________ (Contact details)