## mailx
安装mailx
```
yum install mailx
```
使用mailx发送邮件
```
echo "Hello World" | mail -S smtp=mail.alphabook.cn -r monitor@alphabook.cn -s "test" -v "user01@alphabook.cn"
```
或者
```
mail -S smtp=mail.alphabook.cn -r monitor@alphabook.cn -s "test" -v "user01@alphabook.cn" < /root/message.txt
```
匿名代理(Exchange Anonymous relay)
https://docs.microsoft.com/en-us/exchange/mail-flow/connectors/allow-anonymous-relay?view=exchserver-2019
使用公共邮箱smtp代理
```
echo "Hello World" | mail -S smtp=smtp.163.com -S smtp-auth-user="xxx@163.com" -S smtp-auth-password="xxx" -r from@163.com -s "My Subject" -v "to@163.com"
```
报错1:smtp-server: 535 Error: authentication failed
```
登陆邮箱,启用smtp
密码使用客户端授权密码
```