18.104.22.168.6 vCard Generation
To generate a vCard attachment, clients attach a Contact object, as specified in [MS-OXOCNTC], to a message. For MIME writers, an attached message with a value for the PidTagMessageClass property ([MS-OXCMSG] section 22.214.171.124) that begins with "IPM.Contact" is the trigger for generating a vCard attachment in a MIME message.<102> The vCard format is generated from Contact object properties, as specified in [MS-OXVCARD]. vCard information is included in outbound MIME messages as a file attachment, as specified in section 126.96.36.199.2.2.
The vCard MIME part MUST use a Content-Type header value of "text/directory" with a profile value of "vCard".<103> The character set (2) is set to UTF-8. The vCard content uses quoted-printable encoding, as specified in [RFC2045] section 6.7.