P

Performance console

The Performance console measures the performance of objects in Microsoft Windows Server 2003 and Microsoft Exchange Server 2003 by means of performance counters. The console has two snap-ins: System Monitor and Performance Logs And Alerts.

PKI

See public key infrastructure (PKI).

policy

Policies enable an administrator to configure settings in one location in a flexible manner and have them apply to a large number of users based on their membership in mailbox or public stores, or address lists. When policies are applied, the settings cannot be overridden on an individual basis.

POP3

See Post Office Protocol version 3 (POP3).

port filtering

A firewall-type technology that limits the traffic that can pass from an external network to hosts on an internal network based on port numbers. Port filtering is commonly used to increase protection for Microsoft Exchange Server 2003 servers by limiting communications to only port 25 (SMTP) and possibly 110 and 143 (POP3 and IMAP4, respectively).

Post Office Protocol version 3 (POP3)

An Internet protocol that allows messages to be downloaded from a server to the local computer. This is effective for systems that cannot maintain a continuous connection with the server.

public folder

A collaboration feature of Microsoft Exchange Server that creates a repository of information that is accessible to any user who has been granted permissions to the folder. A public folder can contain mail items, calendar items, task items, or custom forms.

public folder referral

The process by which when a user connects to a public folder store and the store does not contain a copy of the content the user is requesting, Microsoft Exchange Server 2003 automatically redirects the user to a server that does contain the content.

public folder tree

A hierarchy of public folders contained in a public store. There are Default public trees and General Purpose public trees. You can have only one Default public tree in a Microsoft Exchange Server 2003 organization, but you can have multiple General Purpose trees. Messaging Application Programming Interface (MAPI) clients such as Microsoft Outlook and Outlook Web Access (OWA) can only access the Default public tree, but other applications can access General Purpose trees.

public key infrastructure (PKI)

Industry standard technology that allows for the establishment of secure communication between hosts based on a public key/private key or certificate-based system. It is a system of digital certificates, certificate authorities (CAs), and other registration authorities that verify and authenticate the validity of each party involved in an electronic transaction.