What causes folders to be reported as noselect?

[Daniel Miller]

As the subject says.  This may be a bit open-ended - but it would really 
help troubleshooting some obscure folder issues.

In my case, I happen to have both some "real" folders and also some 
"virtual" folders that respond to IMAP LIST commands with the 
"\NoSelect" flag - and I don't know why.  Via telnet, I can manually 
issue SELECT, SEARCH, and FETCH for such folders without errors.

-- 

Daniel