Minor Description
Both of JavaMail and Commons Email encode subjects and personal names with the system property "mail.mime.charset" when no charsets are specified via methods. Also they encode attached filenames with the property when the other system property "mail.mime.encodefilename" is set (regardless of RFC). On the other hand, JavaMail encodes text contents with the property via setText methods when no charsets specified, but Commons Email doesn't encode the contents via setMsg/setTextMsg/setHtmlMsg methods. The partial difference of the behaviors makes confusion.