during installation, sendmail is currently required (meaning that I cannot deselect it during package selection). It should instead be default (meaning that its selected, but can be deselected), for those of us who install postfix instead and have no need for sendmail to be installed currently, I just have to rpm -e sendmail rpm -e sendmail-cf in the %post to work around this bug
It's in the 'core' group, which is always installed anyway, as I recall. So having it default in mailserver won't help your case.
It's not in core It's in base, where it is default like it should be The problem is that it's in mail-server as well, and there it is mandatory instead of default
The issues is that if it's default-but-unselected in mail server, then you have to rely on the comps implementation to DTRT to avoid machines being installed without any mailserver. I don't think this will change at this point.