一般采用yum安装足够用了，安装命令：
#安装sendmail和配置工具sendmail-cf yum install mailx -y yum -y install sendmail yum install -y sendmail-cf
#SMTP认证服务 yum install -y saslauthd |
安装完后，mail的日志位置一般是：/var/log/maillog
测试，有2种方法：
（1） 命令行测试：echo "This is test mail" | mail -s 'Test mail aboutsomething else.' Mchdba@sohu.com
（2） 文件测试：mail -s "test" 1621861384@qq.com < /home/email_content.txt
日志调试参考：
调整日志级别（详细程度）：修改配置文件define(confLOG_LEVEL',16’)dnl 默认为9 ,或者调用命令时指定sendmail-O LogLevel=14，详细参考：http://www.ibm.com/support/knowledgecenter/zh/ssw_aix_71/com.ibm.aix.networkcomm/sendmail_debugflags.htm
这种错误报的比较多，看后台日志，基本信息如下：
Oct 9 14:04:02 localhost sendmail[7902]: restarting /usr/sbin/sendmail due to signal Oct 9 14:04:02 localhost sm-msp-queue[7899]: restarting /usr/sbin/sendmail due to signal Oct 9 14:04:03 localhost sm-msp-queue[8089]: starting daemon (8.14.4): queueing@01:00:00 Oct 9 14:04:03 localhost sendmail[8091]: starting daemon (8.14.4): SMTP+queueing@01:00:00 Oct 9 14:04:13 localhost sendmail[8123]: starting daemon (8.14.4): SMTP+queueing@01:00:00 Oct 9 14:04:13 localhost sm-msp-queue[8131]: starting daemon (8.14.4): queueing@01:00:00 Oct 9 14:04:48 localhost sendmail[8200]: My unqualified host name (ht_121_90) unknown; sleeping for retry |
分析：
系统sendmail时会把以ht_121_90作为域名加到主机名后组成完整的长名ht_121_90. ht_121_90来访问，系统当然就会报“unable to qualify my own domain name (ht_121_90)”
解决方法：
（1）在vim /etc/mail/sendmail.cf 配置文件中查找 Dj$w,并在此行下面增加这一行。
Dj$w.
（2）在/etc/hosts 增加一行
[root@ht_121_90 ~]# more /etc/hosts
127.0.0.1 ht_121_90 ht_121_90. #注意后面有一个点.
192.168.121.90 tracker.powerlong.com
[root@ht_121_90 ~]#
然后重启sendmail服务
[root@ht_121_90 ~]# service sendmailrestart
Shutting down sm-client: [ OK ]
Shutting down sendmail: [ OK ]
Starting sendmail: [ OK ]
Starting sm-client: [ OK ]
[root@ht_121_90 ~]#
再试发送email到qq邮箱，是OK，成功了
[root@ht_121_90~]# mail -s "test" 1621861384@qq.com </home/zhanghaoxiang/data-integration/log/job_dw_main.log
You have new mail in /var/spool/mail/root
[root@ht_121_90 ~]#
查看后台也会显示发送成功了：
Oct 9 14:14:03 localhost sendmail[8345]: u996E3pw008345:to=1621861384@qq.com, ctladdr=root (0/0), delay=00:00:00, xdelay=00:00:00,mailer=relay, pri=48078, relay=[127.0.0.1] [127.0.0.1], dsn=2.0.0, stat=Sent(u996E36P008346 Message accepted for delivery)
Oct 9 14:14:04 localhost sendmail[8348]: STARTTLS=client, relay=mx3.qq.com.,version=TLSv1/SSLv3, verify=FAIL, cipher=RC4-SHA, bits=128/128
Oct 9 14:14:07 localhost sendmail[8348]: u996E36P008346:to=<1621861384@qq.com>, ctladdr=<root@ht_121_90> (0/0), delay=00:00:04,xdelay=00:00:04, mailer=esmtp, pri=138302, relay=mx3.qq.com. [183.57.48.35],dsn=2.0.0, stat=Sent (Ok: queued as )
^C
发送邮件到139邮箱，后台日志报错如下：
Oct 9 14:11:13 localhost sendmail[8330]: u996BDDX008328: to=<mchdba@139.com>, ctladdr=<root@ht_121_90> (0/0), delay=00:00:00, xdelay=00:00:00, mailer=esmtp, pri=120436, relay=mx1.mail.139.com. [221.176.66.188], dsn=5.0.0, stat=Service unavailable Oct 9 14:11:13 localhost sendmail[8330]: u996BDDX008328: u996BDDX008330: DSN: Service unavailable Oct 9 14:11:13 localhost sendmail[8330]: u996BDDX008330: to=<root@ht_121_90>, delay=00:00:00, xdelay=00:00:00, mailer=local, pri=31646, dsn=2.0.0, stat=Sent |
解决：
这种一般是网络问题，网络不能访问139的邮件服务器导致，找网络工程师协调查看下服务器的网络配置。
参考文章：
http://blog.csdn.net/enemyisgodlike/article/details/50723866
http://zdm2008.blog.163.com/blog/static/2049154520139795219380/