Positive Software Corporation has released a new version of IMAP which is fully compatible with H-Sphere. To update to this version of IMAP, Linux owners please use rpm -U instead of rpm -i. FreeBSD users please fist uninstall the old imap server using the pkg_delete <package name> command, then install new imap server. The package name can be determined using the pkg_info | grep imap command.

IMAP installation instructions are available here.