我会尽量多找些有特点的日志，供大家分享
第一段日志，是一段发件方是黑名单：
Thu 2011-08-25 00:02:10: Session 4162; child 2; thread 3372
Thu 2011-08-25 00:01:47: Accepting SMTP connection from [115.117.168.134:21944]
Thu 2011-08-25 00:01:47: --> 220-mail.lenovots.com ESMTP MDaemon 10.1.2; Thu, 25 Aug 2011 00:01:47 +0800
Thu 2011-08-25 00:01:47: --> 220 Novots Technologies Limited
Thu 2011-08-25 00:01:47: <-- EHLO ibgh.com
Thu 2011-08-25 00:01:47: EHLO/HELO response delayed 5 seconds
Thu 2011-08-25 00:01:52: --> 250-mail.lenovots.com Hello ibgh.com, pleased to meet you
Thu 2011-08-25 00:01:52: --> 250-ETRN
Thu 2011-08-25 00:01:52: --> 250-AUTH=LOGIN
Thu 2011-08-25 00:01:52: --> 250-AUTH LOGIN CRAM-MD5
Thu 2011-08-25 00:01:52: --> 250-8BITMIME
Thu 2011-08-25 00:01:52: --> 250-STARTTLS
Thu 2011-08-25 00:01:52: --> 250 SIZE
Thu 2011-08-25 00:01:55: <-- MAIL FROM:<nacha.notification center@nacha.com>
Thu 2011-08-25 00:01:55: Performing PTR lookup (134.168.117.115.IN-ADDR.ARPA)
Thu 2011-08-25 00:01:55: * D=134.168.117.115.IN-ADDR.ARPA TTL=(1439) PTR=[115.117.168.134.static-delhi.vsnl.net.in]
Thu 2011-08-25 00:01:55: * Gathering A records...
Thu 2011-08-25 00:02:07: ---- End PTR results
Thu 2011-08-25 00:02:07: Performing IP lookup (nacha.com)
Thu 2011-08-25 00:02:08: * D=nacha.com TTL=(60) A=[202.94.150.163]
Thu 2011-08-25 00:02:08: * P=010 S=000 D=nacha.com TTL=(59) MX=[mail9.jcity.com] {211.18.210.13}
Thu 2011-08-25 00:02:08: ---- End IP lookup results
Thu 2011-08-25 00:02:08: Performing SPF lookup (nacha.com / 115.117.168.134)
Thu 2011-08-25 00:02:09: * Policy: v=spf1 redirect=jcity.com
Thu 2011-08-25 00:02:09: * Evaluating redirect=jcity.com:
Thu 2011-08-25 00:02:09: * Evaluating redirect=jcity.com: performing lookup
Thu 2011-08-25 00:02:09: * Policy: v=spf1 ip4:211.18.210.0/28 ip4:203.179.86.144/28 ip4:211.9.59.48/28 ip4:219.118.188.80/28 ip4:203.179.83.32/28 ip4:202.94.150.160/28 ip4:61.195.151.208/28 ip4:218.42.158.80/28 ip4:115.31.194.127 ip4:115.31.194.128 ~all
Thu 2011-08-25 00:02:09: * Evaluating ip4:211.18.210.0/28: no match
Thu 2011-08-25 00:02:09: * Evaluating ip4:203.179.86.144/28: no match
Thu 2011-08-25 00:02:09: * Evaluating ip4:211.9.59.48/28: no match
Thu 2011-08-25 00:02:09: * Evaluating ip4:219.118.188.80/28: no match
Thu 2011-08-25 00:02:09: * Evaluating ip4:203.179.83.32/28: no match
Thu 2011-08-25 00:02:09: * Evaluating ip4:202.94.150.160/28: no match
Thu 2011-08-25 00:02:09: * Evaluating ip4:61.195.151.208/28: no match
Thu 2011-08-25 00:02:09: * Evaluating ip4:218.42.158.80/28: no match
Thu 2011-08-25 00:02:09: * Evaluating ip4:115.31.194.127: no match
Thu 2011-08-25 00:02:09: * Evaluating ip4:115.31.194.128: no match
Thu 2011-08-25 00:02:09: * Evaluating ~all: match
Thu 2011-08-25 00:02:09: * Result: softfail
Thu 2011-08-25 00:02:09: ---- End SPF results
Thu 2011-08-25 00:02:09: --> 250 <center@nacha.com>, Sender ok
Thu 2011-08-25 00:02:10: <-- RCPT TO:
检查RBL
Thu 2011-08-25 00:02:10: 执行 DNS-BL 查询（115.117.168.134 - 正在连接 IP）
Thu 2011-08-25 00:02:10: * zen.spamhaus.org - 失败 - 127.0.0.11
Thu 2011-08-25 00:02:10: ---- 结束 DNS-BL 结果
Thu 2011-08-25 00:02:10: --> 550 Your mail server: 115.117.168.134 was listed on RBL by Spamhaus, please contact your system admnistrator, or visit http://zen.spamhaus.org
Thu 2011-08-25 00:02:10: SMTP session terminated (Bytes in/out: 99/425)
发现对方邮箱被加入黑名单，退信并返回信息
第二段日志，DNS解析失败：
Thu 2011-08-25 00:05:21: Session 4186; child 2; thread 4016
Thu 2011-08-25 00:05:14: Accepting SMTP connection from [58.19.99.70:57492]
Thu 2011-08-25 00:05:14: --> 220-mail.lenovots.com ESMTP MDaemon 10.1.2; Thu, 25 Aug 2011 00:05:14 +0800
Thu 2011-08-25 00:05:14: --> 220 Novots Technologies Limited
Thu 2011-08-25 00:05:15: <-- ehlo ufyts.com
Thu 2011-08-25 00:05:15: EHLO/HELO response delayed 5 seconds
Thu 2011-08-25 00:05:20: --> 250-mail.lenovots.com Hello ufyts.com, pleased to meet you
Thu 2011-08-25 00:05:20: --> 250-ETRN
Thu 2011-08-25 00:05:20: --> 250-AUTH=LOGIN
Thu 2011-08-25 00:05:20: --> 250-AUTH LOGIN CRAM-MD5
Thu 2011-08-25 00:05:20: --> 250-8BITMIME
Thu 2011-08-25 00:05:20: --> 250-STARTTLS
Thu 2011-08-25 00:05:20: --> 250 SIZE
Thu 2011-08-25 00:05:20: <-- Rset
Thu 2011-08-25 00:05:20: --> 250 RSET? Well, ok.
Thu 2011-08-25 00:05:20: <-- Mail from:<fyf@ufyts.com>
Thu 2011-08-25 00:05:20: Performing PTR lookup (70.99.19.58.IN-ADDR.ARPA)
Thu 2011-08-25 00:05:21: * Error: * 名称服务器报告未知的域名
Thu 2011-08-25 00:05:21: * No PTR records found
Thu 2011-08-25 00:05:21: ---- End PTR results
检查DNS与MX
Thu 2011-08-25 00:05:21: Performing IP lookup (ufyts.com)
Thu 2011-08-25 00:05:21: * Error: * 名称服务器报告未知的域名
Thu 2011-08-25 00:05:21: ---- End IP lookup results
没有解析，退信并返回信息451
Thu 2011-08-25 00:05:21: --> 451 <ufyts.com> is invalid or DNS says does not exist
Thu 2011-08-25 00:05:21: SMTP session terminated (Bytes in/out: 49/335)
第三段日志，未知的收件人名称：
Thu 2011-08-25 00:07:05: Session 4198; child 2; thread 2560
Thu 2011-08-25 00:06:51: Accepting SMTP connection from [123.89.199.240:1848]
Thu 2011-08-25 00:06:51: --> 220-mail.lenovots.com ESMTP MDaemon 10.1.2; Thu, 25 Aug 2011 00:06:51 +0800
Thu 2011-08-25 00:06:51: --> 220 Novots Technologies Limited
Thu 2011-08-25 00:06:51: <-- ehlo zwag.com
Thu 2011-08-25 00:06:51: EHLO/HELO response delayed 5 seconds
Thu 2011-08-25 00:06:56: --> 250-mail.lenovots.com Hello zwag.com, pleased to meet you
Thu 2011-08-25 00:06:56: --> 250-ETRN
Thu 2011-08-25 00:06:56: --> 250-AUTH=LOGIN
Thu 2011-08-25 00:06:56: --> 250-AUTH LOGIN CRAM-MD5
Thu 2011-08-25 00:06:56: --> 250-8BITMIME
Thu 2011-08-25 00:06:56: --> 250-STARTTLS
Thu 2011-08-25 00:06:56: --> 250 SIZE
Thu 2011-08-25 00:06:56: <-- Rset
Thu 2011-08-25 00:06:56: --> 250 RSET? Well, ok.
Thu 2011-08-25 00:06:58: <-- Mail from:<fd@zwag.com>
Thu 2011-08-25 00:06:58: Performing PTR lookup (240.199.89.123.IN-ADDR.ARPA)
Thu 2011-08-25 00:07:01: * Error: * 名称服务器报告未知的域名
Thu 2011-08-25 00:07:01: * No PTR records found
Thu 2011-08-25 00:07:01: ---- End PTR results
Thu 2011-08-25 00:07:01: Performing IP lookup (zwag.com)
Thu 2011-08-25 00:07:02: * D=zwag.com TTL=(120) A=[209.62.20.188]
Thu 2011-08-25 00:07:02: ---- End IP lookup results
Thu 2011-08-25 00:07:02: Performing SPF lookup (zwag.com / 123.89.199.240)
Thu 2011-08-25 00:07:03: * Result: none; no SPF record in DNS
Thu 2011-08-25 00:07:03: ---- End SPF results
Thu 2011-08-25 00:07:03: --> 250 <fd@zwag.com>, Sender ok
Thu 2011-08-25 00:07:03: <-- RCPT to:<EMailrecruiting@lenovots.com>
Thu 2011-08-25 00:07:03: 发件人试图投递邮件到未知地址
未知收件人地址，退信并返回信息550
Thu 2011-08-25 00:07:03: --> 550 <EMailrecruiting@lenovots.com>, Recipient unknown
Thu 2011-08-25 00:07:05: <-- Quit
Thu 2011-08-25 00:07:05: --> 221 See ya in cyberspace
Thu 2011-08-25 00:07:05: SMTP session terminated (Bytes in/out: 92/390)