Hi Thanh,
Well that is most likely still an issue with your smtp server configuration. To test your smtp server separate from mojoportal, you can telnet into your smtp server and send a test message using smtp commands.
From a command prompt you can telnet to your smtp server like this
telnet hostname 25
where hostname can be the host name for your server or the ip address and 25 is the smtp port
For a list of smtp commands and syntax see
here
Hope it helps.
I will fix the other issue tonight and commit to svn.
Cheers,
Joe