2011.8.26:
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查看/var/log/maillog,发现如下信息:
Aug 25 22:50:48 mail sendmail[2712]: p7PEolPY002712: [113.128.136.151] did not issue MAIL/EXPN/VRFY/ETRN during connection to MTA
Aug 25 22:50:49 mail sendmail[2711]: p7PEokuf002711: [113.128.136.151] did not issue MAIL/EXPN/VRFY/ETRN during connection to MTA
Aug 25 22:50:50 mail sendmail[2713]: p7PEomM3002713: [113.128.136.151] did not issue MAIL/EXPN/VRFY/ETRN during connection to MTA
Aug 25 22:50:53 mail sendmail[2715]: p7PEoojB002715: [113.128.136.151] did not issue MAIL/EXPN/VRFY/ETRN during connection to MTA
Aug 25 22:51:11 mail sendmail[2728]: p7PEp8Sl002728: [113.128.136.151] did not issue MAIL/EXPN/VRFY/ETRN during connection to MTA
这是由于用户连接到MTA以后,没有发任何命令就退出了。举例如下:
在sendmail服务器上,用如下方法监控LOG文件:
tail -f /var/log/maillog
然后,在客户机上,telnet到服务器的25端口
telnet mail.mydomain.com 25
显示如下:
220 mail.mydomain.com ESMTP Sendmail 8.13.8/8.13.8; Fri, 26 Aug 2011 10:16:23 +0800
此时,如果直接键入quit退出,则服务器的log立即就会显示如下一条
p7PEp8Sl002728: [xx.xx.xx.xx] did not issue MAIL/EXPN/VRFY/ETRN during connection to MTA