Here are the steps you can take to confirm an interview appointment by email:

1. Write a clear interview confirmation email subject line.
2. Start your email with a formal greeting.
3. Begin with your reason for sending the email.
4. Restate the interview time and place.
5. Ask questions and confirm what items you’ll need to bring for the interview.
6. Sign off professionally.

Here is an example of an interview confirmation email template you can use:

Subject line: Interview with [Company_name] for the [Job_title] position

Dear [Candidate_Name],

I am contacting you to confirm the date and time of your job interview for [Job_title] position at [Company_name]. The interview will be held on [Date] at [Time] at [Location].

Please let me know if you have any questions or concerns before then.

Thank you for your time and consideration.

Best regards,
[Your Name]

I hope this helps! Let me know if you have any other questions or if there is anything else I can help you with.