centos7 邮件发送失败

当排查crontab 未按预期执行时，想要排查相关日志，发现/var/log/cron文件中输出(root) MAIL (mailed 81 bytes of output but got status 0x004b#012)

1 2	Jun 30 09:26:01 master172 CROND[6846]: (root) CMD (/bin/bash /root/restart_cloudcore.sh) Jun 30 09:26:01 master172 CROND[6845]: (root) MAIL (mailed 81 bytes of output but got status 0x004b#012)

查看/var/log/maillog文件发现

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Jun 30 09:29:01 master172 postfix/sendmail[8262]: warning: valid_hostname: numeric hostname: 16.88.131
Jun 30 09:29:01 master172 postfix/sendmail[8262]: fatal: file /etc/postfix/main.cf: parameter mydomain: bad parameter value: 16.88.131

看上去hostname识别到了一个奇怪的地址16.88.131，联想到这台主机的hostname在安装k8s时修改过，可能posfix识别有问题，这块没找到具体的文章说明。

[root@master172 log]# hostnamectl
   Static hostname: master172.16.88.131
Transient hostname: ctl
         Icon name: computer-vm
           Chassis: vm
        Machine ID: 784df73b2b174ef09ba1249f781baf36
           Boot ID: 646970e7f4494fcf9ea8b22ee9444299
    Virtualization: kvm
  Operating System: CentOS Linux 7 (Core)
       CPE OS Name: cpe:/o:centos:centos:7
            Kernel: Linux 5.16.8-1.el7.elrepo.x86_64
      Architecture: x86-64

修改/etc/postfix/main.cf文件，增加myhostname和mydomain配置

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[root@master172 mail]# cat /etc/postfix/main.cf|grep my
myhostname=master172.16.88.131
mydomain=master172.16.88.131

重启postfix

1	systemctl restart postfix

等crontab执行后，在/var/spool/mail 目录下看到了邮件

1 2	[root@master172 mail]# ls /var/spool/mail/ root sylink