A formal email usually has five main parts that help the reader understand your message clearly. These parts work together to create a message that is easy to follow and professional. When you know each part, you can write emails that leave a good impression. 

The subject line is the first part. It is short, clear, and summarizes the main point of the email in just a few words. A good subject line makes the reader know immediately what the email is about. The greeting comes next and addresses the reader politely. In formal emails, we usually write Dear Mr. Khan or Dear Ms. Ali. The greeting sets the tone and shows respect. 

The opening line and body form the main content of the email. The opening line introduces the purpose politely, such as I am writing to ask about... The body then explains your information, request, or instructions in short, clear sentences. You can also use bullet points for clarity. Keeping your body concise and organized helps the reader understand quickly. 

Finally, every email ends with a closing and a signature. A polite closing can be Thank you for your time, Looking forward to your reply, or Best regards. The signature includes your name and, if necessary, your role or position. This tells the reader who sent the email and how to reach you if needed.