qmail的POP服务的问题

/var/qmail/bin/qmail-popup tom /bin/checkpassword pwd
+OK <7985.1171827907@tom>
user tom
+OK
pass tom
/home/tom
这应该是代表成功的对吧!
然后大家看下面!
telnet fedora.com 110
Trying 192.168.0.12...
Connected to fedora.com (192.168.0.12).
Escape character is '^]'.
+OK <7974.1171827750@pop.fedora.com>
user tom
+OK
pass tom
-ERR authorization first
为什么这里就说验证失败呢!