rmilter v1.10.0 lists libopendkim.so.10 as a dependecy but the currently provided version from the EPEL repository on CentOS 7 is libopendkim.so.11 (libopendkim v2.11.0).
root@server:~# yum install rmilter
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
* base: ftp.plusline.de
* epel: ftp.uni-stuttgart.de
* extras: ftp.plusline.de
* updates: ftp.plusline.de
Resolving Dependencies
--> Running transaction check
---> Package rmilter.x86_64 0:1.10.0-1 will be installed
--> Processing Dependency: libopendkim.so.10()(64bit) for package: rmilter-1.10.0-1.x86_64
--> Processing Dependency: libmilter.so.1.0()(64bit) for package: rmilter-1.10.0-1.x86_64
--> Running transaction check
---> Package rmilter.x86_64 0:1.10.0-1 will be installed
--> Processing Dependency: libopendkim.so.10()(64bit) for package: rmilter-1.10.0-1.x86_64
---> Package sendmail-milter.x86_64 0:8.14.7-4.el7 will be installed
--> Finished Dependency Resolution
Error: Package: rmilter-1.10.0-1.x86_64 (rspamd)
Requires: libopendkim.so.10()(64bit)
You could try using --skip-broken to work around the problem
You could try running: rpm -Va --nofiles --nodigest
rmilter v1.10.0 lists
libopendkim.so.10
as a dependecy but the currently provided version from the EPEL repository on CentOS 7 islibopendkim.so.11
(libopendkim v2.11.0).