Library /sys$common/syshlp/phonehelp.hlb MAIL, Parameters  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 [node::]username

    Specifies the name of the user to receive the mail. Include the
    node when the person you want to receive the message is not on
    your current node.

 "short one-line message"

    Denotes the contents of the message to be sent. The message must
    be enclosed in quotation marks and cannot exceed a single line.