\label{Course_Critical_Message}
A ``Critical Message'' is a message that will appear immediately after the
recipient user logs in. The user must acknowledge receipt to continue; it
is not possible to use the rest of LON-CAPA until they do so. 

Only Course Coordinators and/or Instructors can send Critical Messages.

To send a Critical Message, do the following: 

\begin{enumerate}

\item Select \textbf{Messages} on the Inline Menu or 
\includegraphics[width=0.03\paperwidth]{com}
\textbf{Send and display messages} on the Main Menu.
\item On each of the message sending
screens (\includegraphics[width=0.03\paperwidth]{mail-message-new} 
\textbf{New Message}, 
\includegraphics[width=0.03\paperwidth]{mail-reply-all}
\textbf{New Broadcast Message}, and 
\includegraphics[width=0.03\paperwidth]{fromfile}
\textbf{New Messages from File}), there is a
checkbox \textbf{Send as critical message} which sends this message as a critical message. Selecting \textbf{Yes} in reply to \textbf{"Require return receipt?"} sends the message as a critical message, but additionally returns a
message to you as users acknowledge receipt of the message.

\end{enumerate}