关于mail的问题

我在internet上linux机器的sendmai已经成功发信，但在263上向该linux发信，始终收不到，查看/var/log/maillog如下：
Sep 11 14:26:54 linux sendmail[2148]: f8B6Qrt02148:from=,size=409,class=0, nrcpts=1, msgid=<200109110626.f8B6Qrt02148@linux.future-software.com.cn>, proto=SMTP, daemon=MTA, relay=[202.100.26.228]
Sep 11 14:26:54 linux sendmail[2150]: f8B6Qrt02148: SYSERR(root): MX list for fu
ture-software.com.cn. points back to linux.future-software.com.cn: No such file
or directory
Sep 11 14:26:54 linux sendmail[2150]: f8B6Qrt02148: to=n>, delay=00:00:01, xdelay=00:00:00, mailer=esmtp, pri=30409, relay=future-softw
are.com.cn., dsn=5.3.5, stat=Local configuration error
Sep 11 14:26:54 linux sendmail[2150]: f8B6Qrt02148: f8B6Qst02150: DSN: Local con
figuration error
Sep 11 14:26:59 linux sendmail[2150]: f8B6Qst02150: to=, delay=
00:00:05, xdelay=00:00:05, mailer=esmtp, pri=30509, relay=mx02.263.net. [202.96.
44.26], dsn=5.0.0, stat=Service unavailable
Sep 11 14:26:59 linux sendmail[2150]: f8B6Qst02150: f8B6Qsu02150: return to send
er: Service unavailable
我不清楚到底是dns错误还是sendmail.cf中的错误？
请大家务必指点迷经！！！