UDP (User Datagram Protocol)A connectionless protocol within TCP/IP that corresponds to the transport layer in the International Standard Organization's Open System Interconnect…
UM access telephone numberA telephone number that points to a hunt group and is the access number for calls that are routed to Unified Messaging servers.
Unified MessagingAn application that consolidates a user's voice mail, fax, and e-mail into one mailbox, so that the user only needs to check a single location for…
Unified Messaging server roleA set of components and services that enable voice, fax, and e-mail messages to be stored in a user's single mailbox.
Unreachable queueA persistent queue that contains messages that cannot be routed to their destinations.
Upgradenew or better version of some hardware or software.
URL (Uniform Resource Locator)The Internet address for a document, file, or other resource. It describes the protocol required to access the resource, the host where it can be found…
UsenetThe collection of host computers and networks that exchange news articles organized by subject. [Exchange 5.5]
USENET siteOne or more host computers that run the Network News Transfer Protocol (NNTP). A USENET site is different than an Exchange site. [Exchange 5.5]
User AccountContains information such as the user name, password, group membership, and permissions. [Exchange 5.5]
user profileA group of settings that provides the operating system with information about a client's configuration. [Exchange 5.5]