Please be aware that running nmap locally on a system will give you different results than when run from a remote system. Running nmap on my server locally gives me the following results:
Code:
nmap localhost
Starting Nmap 5.21 ( http://nmap.org ) at 2013-09-03 11:36 PDT
Nmap scan report for localhost (127.0.0.1)
Host is up (0.00024s latency).
Not shown: 991 closed ports
PORT STATE SERVICE
22/tcp open ssh
25/tcp open smtp
80/tcp open http
111/tcp open rpcbind
139/tcp open netbios-ssn
445/tcp open microsoft-ds
2049/tcp open nfs
3306/tcp open mysql
8200/tcp open unknown
While running nmap from my main system, gives me the following result:
Code:
nmap willy
Starting Nmap 6.25 ( http://nmap.org ) at 2013-09-03 11:16 PDT
Nmap scan report for willy (192.168.0.205)
Host is up (0.00031s latency).
Not shown: 993 closed ports
PORT STATE SERVICE
22/tcp open ssh
80/tcp open http
111/tcp open rpcbind
139/tcp open netbios-ssn
445/tcp open microsoft-ds
2049/tcp open nfs
8200/tcp open trivnet1
As you can see from the above results, I have an MTA running, that is only accessible locally, in my case I use logwatch, and check the messages locally on my server. Removing exim4 may render some utilities useless.