socket bind() to port 25 for address (any IPv4) failed: Address already in use:

如果你启动Exim时候发现错误信息:
socket bind() to port 25 for address (any IPv4) failed: Address already in use: waiting 30s before trying again (6 more tries) …. 

这个问题是重复启动导致的 25端口已经被占用了
运行命令
/bin/netstat -lnp | grep 25
查看端口进程号
kill -9  进程号

然后重新启动即可
/sbin/service exim restart