apt-get install bsd-mailx
apt-get install sendmail
vim /etc/mail.rc
set [email protected]
set smtp=smtp.126.com
set [email protected]
set smtp-auth-password=xxx
set smtp-auth=loginvim /etc/hosts
借鉴：https://blog.51cto.com/hades02/1734336
sendmail[20475]: unable to qualify my own domain name （Ajkhuel) -- using short name
于是，google了一下，发现是/etc/hosts文件的问题：
原文件内容：
127.0.0.1localhost
::1 localhostlocalhost.localdomain localhost6 localhost6.localdomain6
192.168.8.66 Ajkhuel
修改后内容：
127.0.0.1localhost
::1 localhostlocalhost.localdomain localhost6 localhost6.localdomain6
192.168.8.66 Ajkhuel abc.mail.com
修改后，重启sendmail服务，邮件发送成功。NOQUEUE: SYSERR(root): opendaemonsocket: daemon MTA-v4: cannot bind: Address already in use
sm-mta[15373]: daemon MTA-v4: problem creating SMTP socket
...vim /etc/mail/access
添加邮箱RELAY
vim /etc/mail/sendmail.mc
dnl DAEMON_OPTIONS(`Port=smtp,Addr=127.0.0.1, Name=MTA')dnl
将前面的dnl去掉，修改为如下：
DAEMON_OPTIONS(`Port=smtp,Addr=0.0.0.0, Name=MTA')dnl m4 /etc/mail/sendmail.mc > /etc/mail/sendmail.cf
/etc/init.d/sendmail restart
systemctl restart sendmail
systemctl start sendmail
systemctl stop sendmail
systemctl status sendmail
echo " Yes , So Good " | mail -s " this is Test Mail " [email protected]
apt-get install -y msmtp