[pauldodman]

X-Cart allows you to choose from various pre-installed templates.
All the templates will use standard files called from common_templates, unless that file has been modified for the particular template you are using.
In which case the template in the other folder is used.
So if you are using the 2-columns template, then the files in that folder are being used, and take precedence over those in common_files.

So in this instance, you need to alter the file in 2-columns/mail

By default, the 2-columns template doesn't have any custom mail templates, so that will explain why they are the same. But as it is in that folder, it is that one that is being used, as opposed to the one in common_files.

However, be aware, that you could change this template and not get the result you were after. If you are using html mail, then the templates will be in the mail/html folder.