You can configure the E-mail confirmation letter text similar to the options for printed confirmation letters. This configuration is done through Maintenance / Online Setup.
The first option enables a preview of the confirmation E-mail before sending. This is recommended, especially if you might want to add special notes to the message for each customer. It will open an E-mail window where you can edit the text or subject of the E-mail as needed before sending.
The Subject for the E-mails should be something fairly generic, but also something that should catch the customer's attention. For instance, include the name of your campground so they know what it's about.
The Letter text may be any length. You can also add line breaks, blank lines, etc. using the Enter key just like typing a letter. The Bottom text can also be any length.
There is also an option to show only the deposit paid and balance due on the confirmation letters, in case you don't want to show details. In addition, when using this option you can show how many adults and children the rate is based on (since the transactions detail information is not shown, this might be important).