Jim Huang wrote:

After met the issue, I set up my hotmail account with HTTP option.
There is no any problem to send out mail with hotmail account. I do
not change any setting on my outlook. Then I try to use other mail
account like 21cn.com, 163.com to test. And there is still no any
problem to send out mail. So I think there is a bug on the outlook
connector. (I can receive mail, but just can not send out mail).

Are the other addresses associated with other accounts in your mail profile
or are you trying to send messages from a 21cn.com or 163.com address
through the Hotmail account?
--
Brian Tillman [MVP-Outlook]