zimbra editon: zcs509 . OS: redhat as 5

Problem one:

logs as follows:

Nov 3 16:29:23 mail2 postfix/qmgr[8755]: 65E8C5FD313: from=<> , size=1349, nrcpt=1 (queue active)
Nov 3 16:29:23 mail2 postfix/smtpd[16868]: disconnect from localhost.localdomain[127.0.0.1]
Nov 3 16:29:23 mail2 postfix/smtp[16865]: 4B9EB5FD30F: to=<173315964@qq.com>, relay=127.0.0.1[127.0.0.1]:10024, delay=0.19, delays=0.06/0/0/0.12, dsn=2.0.0, status=sent (250 2.0.0 Ok: queued as 65E8C5FD313)
Nov 3 16:29:23 mail2 postfix/qmgr[8755]: 4B9EB5FD30F: removed
Nov 3 16:29:30 mail2 postfix/smtp[15220]: 65E8C5FD313: to=<173315964@qq.com>, relay=mx0.qq.com[222.202.96.161]:25, delay=7.2, delays=0.04/0/5.4/1.7, dsn=5.0.0, status=bounced (host mx0.qq.com[222.202.96.161] said: 550 Error: content rejected.退信 - 帮助*心 - QQ邮箱 (in reply to end of DATA command))

when a user auto-reply the senders , the from info is null(as type in red above). But the qq mail system think this is not allowed. So when zimbra users auto-reply qq users, the qq user cannot receive the auto-reply info. This is inportmant for me , some suggestion ?How to solve this ?

Problem two:

In foxmail , I sent a mail to user A in zimbra mail system, and I received the auto-reply info from userA correctly, and then , from the sent folder ,i clicked to resend the mail again , this time ,i cannot received the auto-reply info . Why ?

Need help !!!