sendmail 邮件发送失败重发问题

jerryws

场景：
A机：10.0.2.51, mailserver, （sendmail 8.11.1）
B机：10.0.2.137, 通过A机发送mail
A机上有应用程序会以root@svcchain.chn.hp.com的fromaddress发送邮件到zhiguo.yang@hp.com 和 rvrajesh@hp.com, 接受者立即就收到了。B机上有另一个应用程序会以marketplaceteam@hp.com 的fromaddress发送邮件到marketplaceteam@hp.com和zhiguo.yang@hp.com，发送到marketplaceteam@hp.com的邮件会被提示一句User Unknown,但紧接着还是会被发送出去，而发送到zhiguo.yang@hp.com的邮件则在被提示Connection reset by smtp.hp.com之后放入了队列，过了28分钟（这个时间间隔不一定，有时会是10分钟）后才被发送出去。

问题1：为什么会出现这样的状况？在我看来，要么发送不成功，怎么会在第一次发送失败后，第二次发送就OK了呢？
问题2：队列里面的邮件经过多长时间会被尝试重发？这个时间间隔如何指定？想来应该是在sendmail.cf文件中指定，但我没找到应该修改哪一行。（附件是sendmail.cf文件。）

下面是log信息：
Sep  9 03:35:47 svcchain sendmail[1334]: l88JZlq01334: from=<root@svcchain.chn.hp.com>, size=1193, class=0, nrcpts=1, msgid=<27262916.118
9280146259.JavaMail.root@svcchain.chn.hp.com>, proto=ESMTP, daemon=MTA, [email=relay=root@svcchain.chn.hp.com]relay=root@svcchain.chn.hp.com[/email] [10.0.2.51] (may be forged)
Sep  9 03:35:47 svcchain sendmail[1339]: l88JZlq01339: from=<root@svcchain.chn.hp.com>, size=393, class=0, nrcpts=1, msgid=<22074908.1189
280147554.JavaMail.root@svcchain.chn.hp.com>, proto=ESMTP, daemon=MTA, [email=relay=root@svcchain.chn.hp.com]relay=root@svcchain.chn.hp.com[/email] [10.0.2.51] (may be forged)
Sep  9 03:35:50 svcchain sendmail[1341]: l88JZlq01339: to=<rvrajesh@hp.com>, ctladdr=<root@svcchain.chn.hp.com> (0/3), delay=00:00:03, xd
elay=00:00:03, mailer=esmtp, pri=120393, relay=smtp.hp.com. [192.151.81.254], dsn=2.0.0, stat=Sent (Ok: queued as D966B32E29)
Sep  9 03:35:53 svcchain sendmail[1343]: l88JZrq01343: from=<marketplaceteam@hp.com>, size=1082, class=0, nrcpts=2, msgid=<7945929.118932
[email=6838750.JavaMail.Administrator@hp-gq5repyvd88f]6838750.JavaMail.Administrator@hp-gq5repyvd88f[/email]>, proto=ESMTP, daemon=MTA, relay=hp-gq5repyvd88f [10.0.2.137] (may be forged)
Sep  9 03:35:54 svcchain sendmail[1346]: l88JZrq01343: to=<marketplaceteam@hp.com>, delay=00:00:01, xdelay=00:00:01, mailer=esmtp, pri=15
1082, relay=smtp.hp.com. [161.114.21.254], dsn=5.1.6, stat=User unknown
Sep  9 03:35:54 svcchain sendmail[1346]: l88JZrq01343: to=<zhiguo.yang@hp.com>, delay=00:00:01, xdelay=00:00:01, mailer=esmtp, pri=151082
, relay=smtp.hp.com. [161.114.21.254], dsn=4.4.2, stat=Deferred: Connection reset by smtp.hp.com.
Sep  9 03:35:54 svcchain sendmail[1346]: l88JZrq01343: l88JZsq01346: DSN: User unknown
Sep  9 03:35:57 svcchain sendmail[1346]: l88JZsq01346: to=<marketplaceteam@hp.com>, delay=00:00:03, xdelay=00:00:03, mailer=esmtp, pri=30
893, relay=smtp.hp.com. [192.151.81.254], dsn=2.0.0, stat=Sent (Ok: queued as 8C19B32E25)
Sep  9 03:36:00 svcchain sendmail[1336]: l88JZlq01334: to=<zhiguo.yang@hp.com>, ctladdr=<root@svcchain.chn.hp.com> (0/3), delay=00:00:13,
xdelay=00:00:13, mailer=esmtp, pri=121193, relay=smtp.hp.com. [192.151.81.254], dsn=2.0.0, stat=Sent (Ok: queued as C32BB32F38)
Sep  9 04:00:01 svcchain sendmail[1371]: l88K01b01371: from=root, size=291, class=0, nrcpts=1, msgid=<[email=200709082000.l88K01b01371@svcchain]200709082000.l88K01b01371@svcchain[/email].
chn.hp.com>, [email=relay=root@localhost]relay=root@localhost[/email]
Sep  9 04:00:01 svcchain sendmail[1373]: l88K01b01371: to=root, ctladdr=root (0/3), delay=00:00:00, xdelay=00:00:00, mailer=local, pri=12
0291, dsn=2.0.0, stat=Sent
Sep  9 04:01:02 svcchain sendmail[1380]: l88K12l01380: from=root, size=21278, class=0, nrcpts=1, msgid=<[email=200709082001.l88K12l01380@svcchai]200709082001.l88K12l01380@svcchai[/email]
n.chn.hp.com>, [email=relay=root@localhost]relay=root@localhost[/email]
Sep  9 04:01:02 svcchain sendmail[1382]: l88K12l01380: to=root, ctladdr=root (0/3), delay=00:00:00, xdelay=00:00:00, mailer=local, pri=14
1278, dsn=2.0.0, stat=Sent
Sep  9 04:03:36 svcchain sendmail[1384]: l88JZrq01343: to=<zhiguo.yang@hp.com>, delay=00:27:43, xdelay=00:00:02, mailer=esmtp, pri=241082
, relay=smtp.hp.com. [192.151.81.254], dsn=2.0.0, stat=Sent (Ok: queued as 5D7C132F61)