I write this email to state that my name is _______ (name) and I am working as a __________ (designation) having employee ID _________ (mention ID).
Through this email, I humbly request you to grant me optional leave on date __/__/____ (date) due to ___________ (mention occasion). I hope that you will accept my request and sanction the leave on the date mentioned above.
I hope that you will consider this as a genuine request and approve my request for optional holiday. If you wish to contact me, you can contact me at _________ (contact details).
__________ (Contact details)