[Dovecot] Where's Dovecot's ports?

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@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....