The mailInternetURI represents headers having URI
data type. The URI data type
follows the Uniform Resource Identifier (URI) syntax - a string of characters
that identify some abstract or physical resource in the internet. For more
information, please refer to the Network Working Group's RFC 2396 - Uniform
Resource Identifiers (URI): Generic Syntax.
Generally,
a header having a URI data type has a field value that conforms to the URI
Generic Syntax. The following are examples of URIs: