\begin{tabular}[hbt]{| l || c | c | c |}
	\hline
	Requirement & Importance & Pending work & Focus \\
	\hline \hline
	\RF\,1: In/out channels    & ++ & - & + \\
	\RF\,2: Mail queuing       & ++ & - & + \\
	\RF\,3: Header sanitizing  & 0 & - & - \\
	\RF\,4: Aliasing           & 0 & - & - \\
	\RF\,5: Route management   & + & - & 0 \\
	\RF\,6: Authentication     & ++ & + & +++ \\
	\RF\,7: Encryption         & ++ & + & +++ \\
	\RF\,8: Spam handling      & + & ++ & +++ \\
	\RF\,9: Malware handling   & - & + & 0 \\
	\RF\,10: Archiving         & - & + & 0 \\
	\hline
	\RG\,1: Security           & ++ & + & +++ \\
	\RG\,2: Reliability        & ++ & + & +++ \\
	\RG\,3: Robustness         & + & + & ++ \\
	\RG\,4: Extendability      & + & ++ & +++ \\
	\RG\,5: Maintainability    & + & 0 & + \\
	\RG\,6: Testability        & 0 & 0 & 0 \\
	\RG\,7: Performance        & -{}- & - & -{}-{}- \\
	\RG\,8: Availability       & - & - & -{}- \\
	\RG\,9: Portability        & - & -{}- & -{}-{}- \\
	\RG\,10: Usability         & + & -{}- & - \\
	\hline
\end{tabular}