With some UM services, customers may choose to have e-mail or fax messages reprocessed as audio and read to them over the phone. A customer may respond to any message by calling its sender directly or by dictating a message that the UM center can either deliver by voice or reprocess into text for e-mail. Unified Messaging Ltd. , which claims to have the Internet's first unified messaging service, offers one of the more comprehensive UM systems on the market. Iperia Inc. , Burlington, Mass., has become one of the leading developers of UM software, offering a robust packaged solution to ISPs and next-generation telcos. Service providers can layer it on top of their own communications infrastructure or buy fully configured Windows NT servers capable of handling thousands of customers and drop them into their networks.
Corporate customers can provision specific features for their employees.