To
Name (Write down the name of the Recipient)
Designation (Mention the designation of the Recipient)
Organization (Mention the name of the organization)
Address (Write down the complete address of the Organization)
City/ State (Write the name of the city/ state)
Date (Mention the date on which the letter is being written)
Respected/ Dear Sir/ Ma’am (You may even address the recipient with Mr. /Ms. / Mrs. Last Name)
Subject: Specify the main reason of writing the letter in one line
First Paragraph (Introduce yourself and tell the recipient as to how you got to know about the requirement at their organization)
Second Paragraph (Write about your skills and why you think you are suitable for this internship position)
Third Paragraph (Conclude the letter and state that you would await the response.)
Thanking you
Name (Mention the name of the sender)
Contact Detail (You may even provide your contact details at the end of the letter)