[adamli008]

Now I have installed Domino 8.5.3/BES 5.0.3 MR8 successfully. And I also config following step:
1.config desktop Policy (Encrypt saved mail:Enable)
2.config names.nsf person record(When receiving unencrypted mail, encrypt before storing in your mailfile:yes)
3.create Lotus ID Vault and security policy for ID Vault

After the above step, I can send/receive Notes Native encryption mail from notes client.

On my BlackBerry, Receive mail part:
Now I can receive mail, and read body after type notes id password.
Send mail part:
I can NNE mail to internal mail, but send to internet mail also fail.
The error on Domino server is: Secure messaging: encryption failed for RID=687976639, TID=9002 (The cryptographic key was not found 0x1731)

Does anyone have idea to deal with it.