Qmail hasn't been updated by the author in about seven years.
While others have created updates for it, according to the license terms they cannot be distributed in a compiled or RPM version; each update would have to be installed to the source code in a separate patch before the program is compiled.
And under the Qmail license terms, Dan Bernstein specifically states that the copyright remains his and that he reserves the right to limit or prohibit your right to use it at any time.