The ebuild for cyrus-imapd-2.3.12_p2 doesn't have functional drac support when the USE flag "drac" is turned on. This has happened before, see bug #79442. It's exactly the same problem: drac support does not really get pulled in unless --with-drac=/usr/lib is passed to configure instead of plain --with-drac. Other cyrus 2.3.x ebuilds may also be affected.
Thanks for the report, assigning to maintainers.
Thanks for letting us know, this is fixed in 2.3.13.