Either for the business purposes or for any other personal use, you might have to apply for a loan from a financial institution. Keep in mind that you must have a valid reason for applying for a loan and you have to fulfill all the documentation required.
In the opening paragraph of your email, tell the recipient your purpose of writing the email. Mention that you want to apply for a loan from his/her organization, clearly stating the amount of the money.
In the following paragraph, give a brief introduction of yourself. Tell the recipient about your occupation and how much do you earn on monthly basis. Mention the purpose of applying for the loan. You can also mention your previous experience of obtaining the loan from any other organization and how well you repaid it.
Conclude the last paragraph of your email by praising the loan provider and ask him/her to hold your application in to consideration.