How to leverage any CFMAIL or MTA RateLimiter with SES to set max connections

We employ CFMAIL in a loop to send bursts of 200 messages via Amazon Simple Email Service - every few minutes to an opt-in subscriber list of approx 80K records.
In this way our campaigns take a few hours to complete but our reception and reputation rates remain high. Until recently…

With yesterday’s campaign, some MTAs like AOL / Spectrum / Roadrunner have been pushing back against our traffic, complaining that we (via SES) are making too many connections at once.

AWS does not appear to have any setting to limit its’ number of concurrent outbound connections, but they suggests various Java solutions to employ on our end in similar situations.

Are any of these suggested code snippets (Downscale, RateLimiter, getSleepDuration, etc) already exposed thru Lucee tags, functions or undocumented arguments?

Any suggestions or prior experience solving this one would be helpful. Thanks!

Al Holden

Apache Tomcat/8.5.14
Java 1.8.0_131 (Oracle Corporation) 64bit
Linux (4.15.0-213-generic) 64bit

How many emails can you send per second?

It’s not enough for you to put a pause from an email and the other?
Like this:

    <cfsleep timer=1000> <!--- one second --->
1 Like

Our AWS limit is currently 28 per second. But the complaints come from the down-line MTAs, like the big conglomerate combo that serves AOL, Yahoo, Comcast, Spectrum, Roadrunner and others. So we’re trying to throttle it on our end first, to see if that helps.

The fun part is that these MTA postmasters never cite any thresholds or policies they follow, for fear of tipping off spammers to the specifics. So they just say stuff like “It’s wrong” or “It’s too high, so lower it and try again”.

Yes, I suppose Occam’s razor would point to your solution as the logical first step.

Yes I can imagine. This MTA-hell. Truly. Sometimes getting out of an RBL is really complicated: some sysadmins feel they can do everything without giving you any explanation.

I think so.