Microsoft Exchange Standard Ports

[CFeld]

25: SMTP
53: DNS - Domain Name System
80: HTTP and RVP (for IM initiation)
102: X400
110: POP3
119: NNTP
135: RPC
143: IMAP4
379: LDAP - Site Replication Service
389: LDAP
390: Recommended alternate LDAP for Exchange Server 5.5
443: HTTP (SSL)
465: SMTP (SSL)
522: ULS - User Locator Service
563: NNTP (SSL)
636: LDAP (SSL)
691: SMTP (LSA)
993: IMAP4 (SSL)
995: IRC (SSL)
995: POP3 (SSL)
1503: T.120
1720: H.323
1731: Audio
3268: LDAP - Global Catalog
3269: LDAP (SSL) - Global Catalog (SSL)
6667: IRC

All ports above 1024 are used for RPC