25번 포트쓰는놈이 잇는데 이걸 어떻게 죽여야 하나요?

[root@localhost ~]# systemctl stop  sendmail.service

Failed to stop sendmail.service: Unit sendmail.service not loaded.

[root@localhost ~]# nmap -sT localhost

Starting Nmap 6.40 ( http://nmap.org ) at 2020-01-15 09:45 KST

Nmap scan report for localhost (127.0.0.1)

Host is up (0.00053s latency).

Other addresses for localhost (not scanned): 127.0.0.1

Not shown: 993 closed ports

PORT     STATE SERVICE

25/tcp   open  smtp

80/tcp   open  http

111/tcp  open  rpcbind

631/tcp  open  ipp

1521/tcp open  oracle

2002/tcp open  globe

3306/tcp open  mysql