Sir/ Madam,
My name is __________ (name) and I would like to inform you that I am joining your company on __/__/_____ (date) as _________ (designation). My employee ID is _________ (mention employee ID).
This is to most humbly inform you that I am not clear with the benefits enrollment that includes _________ (medical insurance/ financial security/ educational benefits/ any other). Could you please help me with ______________ (mention your query).
I shall be highly obliged if you could respond to this email at the earliest. Your response is awaited.
Yours truly,
[Digital Signature]
____________ (Signature)
____________ (Name),
____________ (Contact details)