One . mail
You want to send a single email. Here's a simple template you can use:
Subject: [Insert subject line here]
Body:
Dear [Recipient's Name],
[Insert message here]
Best regards, [Your Name]
Email Address: [Your email address]
CC/BCC: [Optional - if you want to CC or BCC someone]
Just fill in the brackets with the relevant information, and you're good to go!