Plesk mail(mailenable) 8bitmime support?

[hypmen]

Hello~
Did everyone ever see the following error message when using plesk/webmail to forward an email.(not all emails appear, but only some specific emails appear it)


here is my plesk/mail system info:
1. OS: win 2008 R2 sp1
2. Plesk: web host edition v12.5.30 Update #24
3. Mail: MailEnable Standard v8

Did anyone has any idea about this question?
How to let plesk or mailenable support 8-bit message data?
Thank to everyone help.