It seems Ilohamail have problem with lotus domino imap servers:
the problem is folder hierarchy separator
while cyrus, courier and others use '/' or '.' as separator
if look at function iil_C_GetHierarchyDelimiter from ./include/imap.inc
- it returns correct value "\\"
but later in ./source/folders.php incorrectly assumes $delimiter to be
one character long.
as result Ilohamail can't access any subfolders on lotus imap servers
also creating any subfolder fails.