Undelivered Email

Undelivered Email

Hi there,

I and my business partners normally get an automatic response to notify invalidate email when sending an email to account: admin.bcnv@bcnv.org.vn / @bcnv.org.vn 

It happens frequently event though the mail is active.  
I would like to send you a sample of the notification in the attachment. 

Pls help me check and fix this problem.
thank you,