Mailing List Message #105804
From: Philip Slater <>
Subject: Re: Unique entries for SMTP Prompt Delay
Date: Thu, 10 Sep 2015 12:51:14 -0700
To: CommuniGate Pro Discussions <>
X-Mailer: Apple Mail (2.1878.6)

On Sep 10, 2015, at 11:39, Tom Rymes <> wrote:

> For a while now, I have had issues receiving mail from a very small number of senders, most of them VERY large companies. I could not figure out why until today because there was never anything in the logs that I could find.
> Today, however, I accidentally discovered that my currently configured prompt delay for SMTP (currently set to 23s) was to blame. While testing, I set the delay to 2s and suddenly a slew of e-mails showed up in my inbox.
> Is there a way that I could assign multiple SMTP listeners, each with a different delay? That way I could use my firewall to direct normal traffic to the normal listener, and direct traffic from senders that do not gracefully handle a longer delay to a separate listener that has no delay (effecitvely creating a whitelist of sorts). I suppose that I could list their IP Addresses and/or DNS names as clients, but that seems to be a Bad Idea™
> I suppose that I could also give these companies a subdomain somehow?
> Tom

The Delay Prompt value is a server wide argument: it cannot be set for a specific  IP address but instead applies to all IP addresses listening.

Additionally, it is not possible to White Hole (UnBlacklistable (White Hole) IP Addresses) the external IP address thereby nullifying its Non-Client IP address status.

Adding the IP address as a client IP address is equally a bad idea unless of course you set the relay settings to “None” which would mean all ‘relay’ operations to be 100% SMTP authenticated. This is because the relay settings only applies to “unauthenticated” relaying.

Otherwise, I know that this does not help but for a sending mail server to give up after 23 seconds does seem unusual as the SMTP protocol has a much longer timeout value.

Other thoughts include

Shorter delay prompt: 15 seconds?

Having the firewall create the “client IP addresses”: Firewall detects the source IP address and instead of passing it to CGP with the “true source IP address” it passes it to CGP as the firewall IP address which could be in the client table.


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