Exchange Common Ports

Agreement	Port	Describe
Smtp	Tcp:25	The SMTP service uses TCP port 25.
Dns	tcp/udp:53	DNS listens on port 53. The domain controller uses this port.
Lsa	tcp:691	The Microsoft Exchange Routing Engine Service (RESVC) listens for routing link state information on this port.
Ldap	tcp/upd:389	This port is used by the Microsoft Active Directory directory service to use the Lightweight Directory Access Protocol (LDAP), the ActiveDirectory connector, and the Microsoft Exchange Server 5.5 directory.
Ldap/ssl	tcp/udp:636	This port is used by LDAP on Secure Sockets Layer (SSL).
Ldap	tcp/udp:379	This port is used by the Site Replication Service (SRS).
Ldap	tcp/udp:390	This is the recommended alternate port for configuring the ExchangeServer 5.5 LDAP protocol when running ExchangeServer 5.5 on an Active Directory domain controller.
Ldap	tcp:3268	The global catalog. Windows 2000 and WindowsServer 2003 Active Directory Global Catalog (Domain Controller "role") to listen on TCP port 3268.
Ldap/sslport	tcp:3269	The global catalog on SSL. Applications that connect to TCP port 3269 on a global catalog server can transmit and receive SSL-encrypted data.
IMAP4	tcp:143	This port is used by Internet Mail Access Protocol (IMAP).
Imap4/ssl	tcp:993	This port is used by IMAP4 on SSL.
POP3	tcp:110	This port is used by Post Office Protocol version 3 (POP3).
Pop3/ssl	tcp:995	This port is used by POP3 on SSL.
NNTP	tcp:119	This port is used by Network News Transfer Protocol (NNTP).
Nntp/ssl	tcp:563	This port is used by NNTP on SSL.
HTTP	Tcp:80	HTTP uses this port.
Http/ssl	tcp:443	This port is used by HTTP on SSL.

This article from the "Struggle for the Dream" blog, declined to reprint!

Exchange Common Ports