Adventures in Mobile Marketing

Letters From the Mailbag: Throttling

I got a great question a few weeks ago (so sorry for the lag!) regarding this:

We’re installing a new commerce server, and recently discovered it has no ability to throttle outgoing emails. A stand-alone server outside of this platform has been configured to distribute our marketing emails, but we have been unable to find a throttling solution for the transactional email server.

Kate, at SuppliesGuys


Frequency control is managed by some tools using business logic that determines exceptions- “only email this person once per day” or “never email this person with a similar promotion for the last 6 months.” The frequency control software I’ve seen has been either manual SQL scripts filtering each outgoing campaign, or part and parcel of an email marketing software solution.

For transactional emails that are triggered by the customer’s activity, it’s not really recommended to introduce a frequency control. Basically because the numbers are rather low, and real-time triggered emails are more appropriate than scheduled marketing emails. If you do have special events- I’ve seen systems support live pay per view wrestling matches that resulted in a very high volume of traffic, and usually launches, releases, or other time-based online traffic generate unusual loads- then throttling is a great idea.

One thing that is a little bit of a fly in the ointment, is that transactional emails and promotional emails have different CAN-SPAM requirements. So I’ve seen these split up in a few different organizations. One system sends the transactional, another sends the opt-in, “once-a-week” promotional emails.

Strongmail is an inhouse solution that is expensive, but I usually point to it to clients if they do want to have real control over transactional & promotional emails in one system, by one IP. There are issues with SM and it’s not the solution for everyone. You can optionally offput those transactional emails to your ESP, and then they control the frequency and throttle for some domains like AOL. The benefit to this is that you have one IP that your client base whitelists. The downside is that it’s a point of risk for any failure, and transactional emails are usually very key to the operational income to your site.

As for freeware that does throttling, I’m not aware of any. I’d actually recommend that as the best solution- keep it inhouse, and setup a “ticker” to count the number of outgoing transactional emails. when it reaches a recommended threshold, setup a delay mechanism.

Thanks and good luck!

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Written on Friday, 19. June 2009 at 09:15 In the category frequency, transactional emails. Follow the comments via RSS here: RSS-Feed. Read the Comments. Trackbacks- Trackback on this post. Share on FriendFeed

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  1. Not sure if I am mixing my terminology here, but I was under the impression that throttling as far as delivery is concerned is the practise of not sending too much email all in one go.

    For example, an ESP will generally throttle the amount of emails going out per Minutes (EPM) and will often apply business logic for the big ISPs who specify how much mail they will process per minute from a single IP address. This is usually around 100 EPM but can sometimes be much lower depending on how an ESP will throttle emails – each one does it differently.

    The idea of only sending out to subscribers as and when they request is frequency control, and not related to throttling sends.

    That is my understanding of it at least!

    Comment: Jake Holman – 19. June 2009 @ 12:25 pm

  2. I agree Jake, frequency control is more the individual’s perception of the frequency, and throttling is the server’s output (hopefully to different individuals). I believe Kate here wants to manage the output of transactional email messages to individuals, which can be intense during specific events.

    Comment: banane – 19. June 2009 @ 1:58 pm

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