Description of problem:
A lot of entries in /var/log/messages saying
SELinux is preventing /usr/bin/exim from search access on the directory net

sealert gives me 

Raw Audit Messages
type=AVC msg=audit(1500377938.962:1304): avc:  denied  { search } for  pid=14113 comm="exim" name="net" dev="proc" ino=7154 scontext=system_u:system_r:exim_t:s0-s0:c0.c1023 tcontext=system_u:object_r:sysctl_net_t:s0 tclass=dir


type=SYSCALL msg=audit(1500377938.962:1304): arch=x86_64 syscall=open success=no exit=EACCES a0=7f12c17314b0 a1=80000 a2=1b6 a3=24 items=0 ppid=14109 pid=14113 auid=0 uid=0 gid=93 euid=0 suid=0 fsuid=0 egid=93 sgid=93 fsgid=93 tty=(none) ses=111 comm=exim exe=/usr/sbin/exim subj=system_u:system_r:exim_t:s0-s0:c0.c1023 key=(null)

I'm pretty sure that the directory exim wants to search is /proc/sys/net.

This happens at times unrelated to any messages sent or received as far as I can see.  It looks likely that the centos7 reports https://bugs.centos.org/view.php?id=13247 and
https://bugs.centos.org/view.php?id=12913 are the same thing, but with different alternative mtas, so the issue is probably not specific to exim, but applies to mtas more generally.

Version-Release number of selected component (if applicable):
selinux-policy.noarch 3.13.1-102.el7_3.16, exim 4.89-1.el7.x86_64 from the exim repository

How reproducible:
It keeps happening

Steps to Reproduce:
1. I don't know how to force it, but it seems to happen roughly hourly, so perhaps it is the byproduct of an hourly cron job.
2.
3.

Actual results:
AVC messages that selinux denies exim permission to search directory net

Expected results:
No AVC messages

Additional info: