Respected Sir/Madam,
This is to most humbly inform you that my name is _________ (name) and I am working in __________ (department) in your reputed organization. I write this email to bring to your attention that I have to attend a family function on __/___/_____(date) for which I have to travel to __________ (city) so I will not be able to come to office for ______ (days).
Therefore, I humbly request you to grant me leave from __/__/_____(date) to __/__/_____(date). I assure you that I will complete all the tasks assigned to me. In case you wish to contact me, I am always available and you can reach me at _________ (contact details).
Thank you,
_____________ (Signature),
_____________ (Name),
_____________ (Designation)