Which capability allows users to receive voicemail messages via e-mail in UC?

The capability that allows users to receive voicemail messages via e-mail is voicemail access on a smartphone. This feature is integral to unified communications (UC), as it enables seamless integration of various communication methods. When users have voicemail messages forwarded to their email, they can listen to these messages directly from their email clients, which enhances productivity and convenience. This capability allows individuals to manage their messages more effectively, especially in a work environment where quick access to communications is critical.

The other options, while related to communication, serve different purposes within a UC framework. Videoconferencing capability focuses on enabling real-time video communication, which does not relate to managing voicemail. Broadcast messaging is typically used for sending mass messages to multiple recipients and does not involve voicemail. Instant messaging allows for real-time text communication but does not encompass the forwarding or management of voicemail messages. Thus, voicemail access on a smartphone is the most directly related capability for receiving voicemail via email in a unified communications system.