Hi for those have the same problem as I had, I tell you how I got it resolved. Inside the Vsphere client 6.0 console, I installed a " mail transfer agents (MTA)" called mutt into the Debian 8 VM.
# apt-get install mutt (For Debian / Ubuntu based system)
Then use the link below to configure mutt.
When the mutt is working now. Send the targeted file by the following command through email attachment.
$mutt -s "Your subject here" email@example.com -a ~/.ssh/rsa
Be noted, your rsa should be chmod-ed opened for the operation. I just got it chmoded to 777 temporarily.
Good luck and fairwell.