Hi Scarab, we're not seeing this same behavior here in our production environments. Below I've included the greylisting response we generate from mail.smartertools.com:

Is this only for IPs blocked by the IDS?

I have a lot of 451 Greylisted in the SMTP logs on 7188. So looks working fine. 

Kyle,

I double-checked our detailed SMTP logs and found not a single 451 responses at all for three months. It would appear that Greylisting is not working at all on Incoming Gateways on build 7188, and hasn't been working for a while. Looking at the Greylisting reports on our Incoming Gateways the last time any connections were Greylisted was 4/15/2019, so apparently it has been not working since the installation of Build 7040 (replacing Build 7016 we had been using previously where Greylisting was working on Incoming Gateways).

Our settings are below:

Went through the Greylisting Bypass list to make sure that there were no Countries listed, or any broad IP Ranges added.

The \Smartermail\Service\Settings\greylist.dat has not been modified by SmarterMail since 4/15/2019 (Build 7040) on all of our Incoming Gateways. Renaming this file and restarting the Smartermail Service (on Build 7188) does not recreate this file either.

Thanks @Scarab, I'm going to spin up some testing on this now and will reach out to update you when I find out more. You may want to get a ticket submitted so we can really dig into this. Thanks!

I did a quick test on a brand new b7188 install and found greylisting is functioning here at least, so either the issue has since been resolved, or it is something specific to your environment. Could you open a ticket and submit your greylist.dat so I can check it out in more detail?

Thanks! Glad to hear you found this :)