Why I away got "Stack connect fail" or "MX MX connect fail"?

[2131323]

Now, I move my email system to a new dedicated server (windows 2003), when I send out e-mail, I aways got error, and I have change DNS too many times, reinstall 3 times, but I can not make it work.

thanks a lot
log:
SYSLOGD 7.15 EVAL, Copyright ? 1994-2001, Ipswitch, Inc.
20060225 001355 0.0.0.0:514 Server ready for action
20060225 001355 127.0.0.1 SMTPD (000400A0) server starting on port 25 of cecece.com
20060225 001407 127.0.0.1 SMTPD (00FA00B6) [11.178.158.67] connect 11.178.158.67 port 3352
20060225 001507 127.0.0.1 SMTPD (00FC00B6) [11.178.158.67] connect 11.178.158.67 port 3355
20060225 001513 127.0.0.1 SMTPD (0005007E) server starting on port 25 of cecece.com
SYSLOGD 7.15 EVAL, Copyright ? 1994-2001, Ipswitch, Inc.
20060225 001617 0.0.0.0:514 Server ready for action
20060225 001642 127.0.0.1 SMTPD (00050072) [11.178.158.67] connect 11.178.158.67 port 3363
20060225 001710 127.0.0.1 SMTP (2544) processing C:\IMail\spool\Q36959350290.GSC
20060225 001725 127.0.0.1 SMTP (2544) Trying 163.com (0)
20060225 001742 127.0.0.1 SMTPD (003500AA) [11.178.158.67] connect 11.178.158.67 port 3373
20060225 001748 127.0.0.1 SMTP (2544) Stack connect fail "220.181.29.154"
20060225 001748 127.0.0.1 SMTP (2544) requeuing C:\IMail\spool\Q36959350290.GSC R0 T1
20060225 001748 127.0.0.1 SMTP (2544) finished C:\IMail\spool\Q36959350290.GSC status=3
20060225 001842 127.0.0.1 SMTPD (003700AA) [11.178.158.67] connect 11.178.158.67 port 3379
20060225 001942 127.0.0.1 SMTPD (003900AA) [11.178.158.67] connect 11.178.158.67 port 3382