Qmail out of the box works fine, so people will want to use it regardless of licensing restrictions, even when the software does not ship with their system software.
Wietse VenemaIn a previous life I wrote the software that controlled my physics experiments. That software had to deal with all kinds of possible failures in equipment. That is probably where I learned to rely on multiple safety nets inside and around my systems.
Wietse VenemaWhen I write software, I know that it will fail, either due to my own mistake, or due to some other cause.
Wietse Venema