VPIM
Voice Profile for Internet Mail (VPIMv2) is defined in RFC 3801, an Internet standards track protocol.
VPIM defines a subset of the Internet multimedia messaging protocols (MIME) for use between voice processing server platforms.
This and related protocols define the familiar myEmailAddress@myDomain.com type of e-mail addressing everyone now uses on the internet, extending it from regular e-mail to voice mail and fax systems.