List of Ports used by Exchange Server

Protocol

Port

Description

SMTP

TCP: 25

The SMTP service uses TCP port 25.

DNS

TCP/UDP: 53

DNS listens on port 53. Domain controllers use 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

Lightweight directory access protocol (LDAP) used by Microsoft Active Directory® directory service, Active Directory Connector, and the Microsoft Exchange Server 5.5 directory use this port.

LDAP/SSL

TCP/UDP: 636

LDAP over Secure Sockets Layer (SSL) uses this port.

LDAP

TCP/UDP: 379

The Site Replication Service (SRS) uses this port.

LDAP

TCP/UDP: 390

This is the recommended alternate port to configure the Exchange Server 5.5 LDAP protocol when Exchange Server 5.5 is running on an Active Directory domain controller.

LDAP

TCP: 3268

Global catalog. The Windows 2000 and Windows Server 2003 Active Directory global catalog (a domain controller "role") listens on TCP port 3268.

LDAP/SSLPort

TCP: 3269

Global catalog over SSL. Applications that connect to TCP port 3269 of a global catalog server can transmit and receive SSL encrypted data.

IMAP4

TCP: 143

Internet Message Access Protocol (IMAP) uses this port.

IMAP4/SSL

TCP: 993

IMAP4 over SSL uses this port.

POP3

TCP: 110

Post Office Protocol version 3 (POP3) uses this port.

POP3/SSL

TCP: 995

POP3 over SSL uses this port.

NNTP

TCP: 119

Network News Transfer Protocol (NNTP) uses this port.

NNTP/SSL

TCP: 563

NNTP over SSL uses this port.

HTTP

TCP: 80

HTTP uses this port.

HTTP/SSL

TCP: 443

HTTP over SSL uses this port.