Respected Sir/Madam,
Through this email I would like to inform you that my name is __________ (name) and I am working as a ___________ (designation) having employee ID ____________ (mention ID). I write this email to request you to provide me with a reference letter as I need this document for rental agreement.
I hope that you will accept my request and process my request for issuance of a reference letter as soon as possible. If you wish to contact me, please do not hesitate to contact me at ___________ (contact details)
Yours sincerely,
____________ (Name)
____________ (Designation)
____________ (Contact details)