In CentOS (RedHat), the sendmail and sm-client start slowly. If you need a solution, please refer to this article.
Starting sendmail:
Starting sm-client:
After I posted an article about modifying the host name, I accidentally found that when CentOS was restarted, the system would be stuck in sendmail and sm-client for nearly three minutes, I found the sendmail and sm-client documents and found that I had made an error.
The reason is that sendmail and sm-client are both MTA and only the network host name, such as admin.slyar.com. localdomain is changed to Slyar, which does not comply with the network host name specification, so the startup speed is slow. The solution is as follows:
1. Change the host name under/etc/sysconfig/network to the network host name Slyar. localdomain.
# Vim/etc/sysconfig/network
2. Change the host name under/etc/hosts to the network host name Slyar. localdomain.
# Vim/etc/hosts
3. restart the system so that the system will not be slow in the future.
# Reboot