Get email subject and body from email template – D365 finance and operations

        SysEmailTable                   sysEmailTable;
        SysEmailMessageTable            sysEmailMessageTable;
        SysEmailContents                sysEmailContents;
        str                             subject, body;
        SysEmailId                      emailTemplateId = 'DlvNote'; //email template name
        LanguageId                      language = 'en-US';
               

        select sysEmailTable
               join sysEmailMessageTable
                where sysEmailMessageTable.EmailId==sysEmailTable.EmailId
                    && sysEmailMessageTable.EmailId== emailTemplateId
                    && sysEmailMessageTable.LanguageId==language;

        subject = SysEmailMessage::stringExpand(sysEmailMessageTable.Subject, mappings); //mappings = placeholders
        body    =  SysEmailMessage::stringExpand(sysEmailMessageTable.Mail, mappings);