I did an "in house" course on Twain at Western Michigan University a couple
of years ago.  It was not on e mail but a system called CONFER. It worked
very well.  Sounds like a fine idea but I doubt that the Forum would want to
manage it.  Too much work responding to students.   I am doing seminars for
seniors here in Arizona now and they would love to see a Twain course on
line.  Most of them are very curious, intelligent, eager, and know the
computer.