Mysql – Having trouble installing MySQL Community Server on new RHEL 6.8 instance

I'm having trouble installing MySQL 5.7.12 on RHEL 6.8.

The first RPM I downloaded was for RHEL 7.0. This is a brand new instance, and I stupidly assumed it would be RHEL 7. It's not.

So my installation failed with errors like:

Error: Package: mysql-community-server-5.7.12-1.el7.x86_64 (mysql57-community)
       Requires: libc.so.6(GLIBC_2.17)(64bit)
Error: Package: mysql-community-server-5.7.12-1.el7.x86_64 (mysql57-community)
       Requires: systemd
Error: Package: mysql-community-libs-5.7.12-1.el7.x86_64 (mysql57-community)
       Requires: libc.so.6(GLIBC_2.14)(64bit)
Error: Package: 2:postfix-2.6.6-6.el6_7.1.x86_64 (@rhel-x86_64-server-6)
       Requires: libmysqlclient.so.16()(64bit)

That's when I looked at the version and found it was 6.8. So I did:

sudo rpm -e mysql57-community-release-el7-8.noarch

and removed it. I added the repo for RHEL6 with:

wget http://dev.mysql.com/get/mysql57-community-release-el6-8.noarch.rpm

and:

sudo yum localinstall mysql57-community-release-el6-8.noarch.rpm

and:

sudo yum install mysql-community-server

But I still get these failures:

Error: Package: mysql-community-server-5.7.12-1.el7.x86_64 (mysql57-community)
       Requires: libc.so.6(GLIBC_2.17)(64bit)
Error: Package: mysql-community-server-5.7.12-1.el7.x86_64 (mysql57-community)
       Requires: systemd
Error: Package: mysql-community-libs-5.7.12-1.el7.x86_64 (mysql57-community)
       Requires: libc.so.6(GLIBC_2.14)(64bit)
Error: Package: 2:postfix-2.6.6-6.el6_7.1.x86_64 (@rhel-x86_64-server-6)
       Requires: libmysqlclient.so.16()(64bit)
       Removing: mysql-libs-5.1.73-7.el6.x86_64 (@rhel-x86_64-server-6)

Notice that first line. It still says el7. Did removing the rpm for MySQL RHEL7 not get rid of everything? Also, it still says it requires systemd, but there's no systemd anywhere I can find on this 6.8 install. I appreciate the help, I know that I'm missing something basic here.