Appian email messages use standard header and footer HTML files that you can update to suit your applications. The header and footer files are stored as Appian documents.
The file encoding used is UTF-8. Any HTML updates to these files must be encoded in UTF-8, if Unicode is used for the file encoding.
The header and footer files are created the first time Appian is started after installation. Restarting the application server will preserve any changes you've made to these files, but will restore any of these files that may have been inadvertently deleted.