LibMAIL is partially based
    on libraries used in implementing the Courier
    mail server. As such, the library contains both C and C++
    code; although the published API consists of C++ objects only.
    LibMAIL uses C++ objects
    declared in the mail namespace.
    Applications that use LibMAIL
    should refrain from declaring any objects in the mail namespace. At this time, applications
    should also refrain from declaring any C functions whose name
    begin with the following prefixes (these prefixes are reserved
    at this time):