Can't send mail

[Ke Lu]

Hi there,

I use ntemacs to sendmail and got a error.
open-network-stream: make client process failed: software caused connection 
abort, :name, SMTP, :buffer, *trace of SMTP session to xxx.xxx.xx*, :host, 
xxx.xxx.xx, :service, 25
The following is my setting.
(setq smtpmail-auth-credentials
    '(("xxx.xxx.xx"
           25
           "xxxxxx";; Userid
           nil)))   ;; Passwd
(setq smtpmail-default-smtp-server "xxx.xxx.xx")
(setq smtpmail-smtp-server "xxx.xxx.xx")
(setq message-send-mail-function 'smtpmail-send-it)
                         
I have the same setting in linux and works well.
What's wrong?