Send Mail error On freebsd,sendmail

[eluser]whidbey[/eluser]
I use my local freebsd server,dont have smtp user.
so I not fill smtp_user ,smtp_pass field.
I check my stmp server,it runs on 25 port ok,and
when I telnet localhost 25,
I can get the reply:
250-ENHANCEDSTATUSCODES
250-PIPELINING
250-EXPN
250-VERB
250-8BITMIME
250-SIZE
250-DSN
250-ETRN
250-AUTH LOGIN PLAIN
250-DELIVERBY
250 HELP

so smtp server is running ok.

and my /etc/mail/access accept local access already..
so I dont know how next..

by the way,I use default charset utf-8 to send mail.

thx