sendmail问题！

zhjack

小弟用Linux9+openwebmail+sendmail架设电邮系统，但发信时出现以下提示，请问如何解决！多谢。。。
最好说详细些，新手啊！！

-----------------------------------------------------------------------------------
<<< 220 Linux2 ESMTP Sendmail 8.12.8/8.12.8; Fri, 15 Oct 2004 22:46:33 +0800
>;>;>; EHLO XXX.com
<<< 250-Linux2 Hello localhost.localdomain [127.0.0.1], pleased to meet you
<<< 250-ENHANCEDSTATUSCODES
<<< 250-PIPELINING
<<< 250-8BITMIME
<<< 250-SIZE
<<< 250-DSN
<<< 250-ETRN
<<< 250-DELIVERBY
<<< 250 HELP
>;>;>; MAIL FROM:<XXXX@XXX.com>;
<<< 554 5.3.5 buildaddr: no user
--------------------------------------------------------------------------------