A partial list of the ports your Exchange server might use is included below

* 25 SMTP

* 53 DNS

* 80 HTTP

* 88 Kerberos

* 102 X.400

* 110 POP3

* 119 NNTP

* 135 RPC

* 137 - NetBIOS Session Service

* 139 - NetBIOS Name Service

* 143 IMAP4

* 379 LDAP (SRS)

* 389 LDAP

* 443 HTTP (SSL)

* 445 - NetBIOS over TCP

* 465 SMTP (SSL)

* 563 NNTP (SSL)

* 636 LDAP (SSL)

* 691 LSA

* 993 IMAP4 (SSL)

* 994 IRC (SSL)

* 995 POP3 (SSL)

* 1503 T.120

* 1720 H.323

* 1731 Audio conferencing

* 1863 - MSN IM

* 3268 GC

* 3269 GC (SSL)

* 6001 Rpc/HTTP Exchange Store

* 6002 HTTP Exchange Directory Referral service

* 6004 Rpc/HTTP NSPI Exchange Directory Proxy service/Global Catalog

* 6667 IRC/IRCX

* 6891 - 6900 - MSN IM File transfer

* 6901 - MSN IM Voice

* 7801 - 7825 - MSN IM Voice