lephone. Additionally, they contain presence indicators that show the availabil- ity of people in their group. Figure 2-8 depicts a UC inbox that is part of Microsoft Lync. Many UC systems offer audio and video conferencing capability from users' computers. An important advantage of UC systems is the ability of people who travel to have the convenience of checking only one source for messages and sharing information with others via audio and video conferencing. Retrieving messages from PCs, tablets, Paul Koch Paul Koch Call PRODUCT DESIGNER Options for communicating within unified messaging include: E-mail Instant messaging Telephone Video conferencing BATAM BELAM Figure 2-8 An example of a Unified Communications (UC) system applica- tion. (Used with permission of Microsoft.) Data Centers and IP Private Branch Exchanges and smartphones also affords users the ability to prioritize messages and listen to the most important ones first. It eliminates the need to hear all voicemail messages before getting to the critical ones. When users access messages from a touch-tone phone, text-to-speech software converts e-mail to speech for callers and reads their e-mail messages to them. Employ- ees access messages through e-mail software on their PCs or remotely on their mobile devices. UC systems need to be compatible with e-mail programs such as Microsoft Exchange and Lotus Notes. Systems typically also support e-mail retrieval from within browsers SO that remote workers can retrieve messages from their PC and listen to them through the PC's speaker. IP PBX providers supply the majority of UC systems. This gives customers single-source support for their phone and messaging systems. The Declining Use and Criticality of Voicemail Voicemail use is declining. This is due in large part to increasing dependence on e-mail and instant messaging and faster responses to e-mail as a result of its integration on tablet computers and smartphones such as the BlackBerry and Apple iPhone. Voice- mail for mobile services is also declining b