Awesome article on credentials https://help.ubuntu.com/community/MountWindowsSharesPermanently
//10.xxx.xxx.xxx/closed\040files/ /media/closed_files cifs credentials=/home/tech/.smbcredentials,_netdev,iocharset=utf8,sec=ntlm 0 0
or
//10.xxx.xxx.xxx/closed\040files/ /media/closed_files cifs username=****,password=****,_netdev,iocharset=utf8,sec=ntlm 0 0
use \040 as filler for spaces in source file name
create the /media/target folder ahead of time
_netdev option causes mount to happen after network is up.
create the credentials file like so:
username:username
password:password