Non-root user user attempt to run mailx or sendmail fails with (egid=##, want=51)

Issue

Non-root user user attempt to run mailx or sendmail fails with (egid=##, want=51)

[user@rhel6-4 ~]$ echo test | mailx -s test user
WARNING: RunAsUser for MSP ignored, check group ids (egid=25, want=51)
can not chdir(/var/spool/clientmqueue/): Permission denied
Program mode requires special privileges, e.g., root or TrustedUser.

Changing permission of /var/spool/clientmqueue/ to allow read, write, execute for all users (ie. chmod 777) does allow message to be delivered. However, warning message is still produced along with additional message sent to syslog. Note This additional warning in syslog exists as opening permissions to /var/spool/clientmqueue is a security risk.

[user@rhel6-4 ~]$echo test | mailx -s test user
WARNING: RunAsUser for MSP ignored, check group ids (egid=25, want=51)

[root@rhel6-4 mail]# tail -n 5 /var/log/maillog | grep dangerous
Sep  4 15:48:59 rhel6-4 sendmail[23522]: dangerous permissions=40777 on queue directory /var/spool/clientmqueue/