You have chosen to encode attachment names containing non-English characters in a way that is understood by Outlook(tm) and other mail clients that do not support standard-compliant encoded attachment names. Note that KMail may create non-standard compliant messages, and consequently it is possible that your messages will not be understood by standard-compliant mail clients; so, unless you have no other choice, you should not enable this option
प्रमाणपत्रKDE40.1 KDE40.1