14 Chapter 2 Configuring your system for Unified MessagingN0060611N0060611IMAP lets subscribers check for messages from any location with an Internet connection. IMAPalso lets subscribers access messages from multiple locations. IMAP is a method of accessingelectronic mail or bulletin board messages that are kept on a shared mail server. IMAP lets a cliente-mail program access remote message stores as if they were local. For example, e-mail stored onan IMAP server can be accessed from a computer at home, a workstation at the office, and anotebook computer while traveling, without the need to transfer messages or files between thesecomputers.LDAPLightweight Directory Access Protocol (LDAP) is a set of protocols for accessing informationdirectories. LDAP supports TCP/IP, which is necessary for any type of Internet access. LDAP letsa client search for and use information entries on a directory server, such as the BusinessCommunications Manager. For example, a typical entry in the CallPilot directory containsattributes of a subscriber such as name, telephone number, and CallPilot mail address. Internetclients can use LDAP to query address book information from the CallPilot directory, performaddress resolution, or search for specific subscribers (if this functionality is implemented by theInternet client).SMTPSimple Mail Transfer Protocol (SMTP) is a protocol for sending e-mail messages between servers.Most e-mail systems that send mail over the Internet use SMTP to send messages from one serverto another. These messages can then be retrieved with an e-mail client using IMAP. SMTP is alsogenerally used to send messages from a mail client to a mail server. This is why you must specifyboth the IMAP server and the SMTP server when you configure your e-mail application.Since Voice Profile for Internet Mail (VPIM) Networking also uses SMTP, you do much of theconfiguration for IMAP in the same places you set up VPIM Networking.Configuring environments without a DNSThe Domain Name System (DNS) is an Internet service that translates domain names into IPaddresses. Because domain names are alphabetic, they are easier for subscribers to remember. TheInternet is based on IP addresses. Every time you use a domain name, therefore, a DNS musttranslate the name into the corresponding IP address. For example, the domain namewww.example.com can translate to 198.105.232.4.If one DNS server does not know how to translate a particular domain name, it asks another one,and so on, until the correct IP address is returned.Unified Messaging uses Domain Name resolution, which is provided by a DNS. If your networkdoes not have a DNS, then you must configure Unified Messaging to use IP addresses.Note: Unified Messaging clients require LDAP authentication of the CallPilotmailbox directory number and password to begin a search on a BusinessCommunications Manager LDAP directory.