ACL v4.8 - How To Reject Uknown Users -Before- RBL Checks


Well-Known Member
Feb 28, 2005
North Carolina
ACL v4.8 - Reject Uknown Users Before RBL Checks ?

Is there an easy modification to the ACL Template V4.8 (via the Advanced Editor) so that unknown users are rejected prior to RBL checks taking place?

I've got a client scenario where a fair amount of bandwidth is being used on calls to Spamhaus etc. for mail that arrives for unknown users (all accounts are set to :fail:). The junkmail is rejected after the RBL check, but in looking at the logs, a significant portion of this is addressed to users that do not exist in the first place.

Is it as simple as moving (or copying) require verify = recipient above [% ACL_RBL_BLOCK %]?

Thanks -
Last edited:


Well-Known Member
Feb 22, 2003
With the usual caveat emptor disclaimers etc, I do believe that's what you'd need to do (at your own risk) :D

I would also ensure that [% ACL_PRE_RECP_VERIFY_BLOCK %] is kept above "require verify = recipient", to ensure that Dictionary Attacks are dealt with appropriately.