[Dovecot] Where's Dovecot's ports?

[Mohsen Pahlevanzadeh]

Dear all,

I installed "dovecot dovecoot-mysql postfix and postfix-mysql" from
debian repository 7.

I start them with "/etc/init.d/postfix start" and "/etc/init.d/dovecot
start" 

but When i use nmap localhost I see the following output:
root at sito:/etc/dovecot# nmap localhost 

Starting Nmap 6.00 ( http://nmap.org ) at 2013-09-12 07:35 IRDT
Nmap scan report for localhost (127.0.0.1)
Host is up (0.0000030s latency).
Other addresses for localhost (not scanned): 127.0.0.1
Not shown: 993 closed ports
PORT     STATE SERVICE
21/tcp   open  ftp
22/tcp   open  ssh
25/tcp   open  smtp
80/tcp   open  http
111/tcp  open  rpcbind
3128/tcp open  squid-http
3306/tcp open  mysql

My Question is , Where's dovecot ? i don't see its' ports....