Error: Package: 2:postfix-2.6.6-8.el6.x86_64 (@os)
           Requires: libmysqlclient.so.16()(64bit)
           Removing: mysql-libs-5.1.73-8.el6_8.x86_64 (@os)
               libmysqlclient.so.16()(64bit)
           Obsoleted By: mysql-community-libs-5.7.22-1.el7.x86_64 (mysql57-community)
               Not
 
 found
Error: Package: mysql-community-server-5.7.22-1.el7.x86_64 (mysql57-community)
           Requires: libc.so.6(GLIBC_2.17)(64bit)
Error: Package: mysql-community-server-5.7.22-1.el7.x86_64 (mysql57-community)
           Requires: systemd
Error: Package: 2:postfix-2.6.6-8.el6.x86_64 (@os)
           Requires: libmysqlclient.
 
so.16(libmysqlclient_16)(64bit)
           Removing: mysql-libs-5.1.73-8.el6_8.x86_64 (@os)
               libmysqlclient.so.16(libmysqlclient_16)(64bit)
           Obsoleted By: mysql-community-libs-5.7.22-1.el7.x86_64 (mysql57-community)
               Not found
Error: Package: mysql-community-client
 
-5.7.22-1.el7.x86_64 (mysql57-community)
           Requires: libc.so.6(GLIBC_2.14)(64bit)
Error: Package: mysql-community-libs-5.7.22-1.el7.x86_64 (mysql57-community)
           Requires: libc.so.6(GLIBC_2.14)(64bit)
Error: Package: mysql-community-server-5.7.22-1.el7.x86_64 (mysql57-community)
           Requires: libstdc++.so.6(GLIBCXX_3.4.15)(64bit)
Error: Package: mysql-community-server-5.7.22-1.el7.x86_64 (mysql57-community)
           Requires: libsasl2.so.3()(64bit)
Error: Package: mysql-community-client-5.7.22-1.el7.x86_64 (mysql57-community)
           Requires: libstdc++.so.6(GLIBCXX_3.4.15)(64bit)

可以肯定這是系統版本的問題，centos7以下的，建議升級系統或者使用yum安裝