I was going to report that even though authenticated user mail was not being spam checked any more, it was still being checked against RBLs. However, after reviewing the bug linked above, the fix from Quanah Gibson-Mount seems to have fixed it for me!
In terms of the zimbraMtaRestriction vs zimbraMtaRestrictionRBL, here's what my server returns:
Originally Posted by Quanah Gibson-Mount
zimbra@cottontail:~$ zmprov gacf | grep -i zimbraMtaRestriction
zimbraMtaRestriction: reject_rbl_client b.barracudacentral.org
zimbraMtaRestriction: reject_rbl_client zen.spamhaus.org
zimbraMtaRestriction: reject_rbl_client dnsbl.njabl.org
zimbra@cottontail:~$ zmprov gs `zmhostname` | grep -i zimbraMtaRestriction
We upgraded from 6.0.14 to 8.0.2, which I'm sure makes a difference. We only add/remove RBLs through the admin GUI and rarely (if ever) make config changes via any of the CLI tools. Also, when I make RBL changes post 8.0.2 upgrade, they still seem to apply as "zimbraMtaRestriction: reject_rbl_client xxx". This is just an FYI more than anything else.
zimbra@cottontail:~$ zmlocalconfig | grep -i zimbraMtaRestriction