
The power of marketing automation is right there in the name: automation. But it’s essential to take precautions and set limits, lest you suffer a fate similar to Mickey Mouse in the Sorcerer’s Apprentice, where your efficient and empowered implements make an even bigger mess than you started with. Fortunately, Marketo has built-in email communication limits to help you control the number of emails an individual can receive in a given period.
What is an email communication limit?
In the US, the average professional has more than 200 emails in their inbox and will receive 120 new ones each day. How do you prevent your emails from adding to the noise, especially once automated?
Enter: Marketo email communication limits. You can limit the number of emails sent to one person with settings in Marketo. It’s a great feature, but the UI is not intuitive and documentation is spotty. So we scoured Marketo product documentation, community boards and did our own testing to bring you definitive answers.

There are three parts to configure at the admin level: per day, per week, and block non-operational emails.
Marketo defines “per day” as a calendar day from midnight-midnight in your subscription time zone. Your options include unlimited as well as custom, which will allow you to specify any number.
Next, you can set the maximum number of emails sent per 7 days. For example, if you allow 1 email per day, you may want to only allow 5 emails per week.
You may be looking for a magic formula to determine the appropriate number of emails, but that is entirely dependent on your audience.
What counts against the limit?
It’s relatively easy to decide not to schedule more than X promotional emails in a week, but what about the emails necessary to conduct business?
Transactional emails, such as confirmations, alerts, or other notifications can—and should—be set as Operational. Operational emails ignore Marketo Unsubscribed and Marketing Suspended statuses. Moreover, they can be excluded from email communication limits, both globally and locally at the individual campaign level.
Additionally, if you use Marketo Sales Insight, don’t worry. Emails sent with MSI do not count towards your email communication limit.
What happens when someone reaches the limit?
In short: it depends. It depends on both the individual email settings and the campaign used to send it.
First, the most basic. Emails that are scheduled or designed to send upon a triggering event via a default or email program will be skipped. Marketo will not try to resend the email automatically.
If the email is part of an engagement program, leads over the email communication limit will not receive that cast. However, the lead can re-qualify and receive the skipped email during the next cast.

That brings us to operational emails, those essential to conducting business. At the admin level, you can select whether or not Marketo will block non-operational emails as part of your global communication limit. It’s almost a double negative, so it may help to think of it instead as “allow operational emails.” If you have checked the box for this setting, emails set as operational are excluded from the limit and will still send, generally speaking. We’ll dive into these settings a little later.
Finally, what about seed lists where you need someone to receive every email every time regardless of email communication limits? You can trick Marketo and use the “Send Alert” flow step instead of “Send Email.” Sending the email as an alert to your seed list will effectively ignore the email communication limit settings and is useful when testing your campaigns. Check out our post on how to unblock your seed list for detailed instructions.
Where should I set the email communication limits?
Email communication limits set at the admin level serve as the “default” for all campaigns created. However, individual smart campaign and email program settings can override the admin setting. Digital Pi Gold Standard typically advises to do as much set up globally as possible, so your instance can scale.
Things to consider before changing your email communication limits
Before you enable, disable or otherwise change your global email communication limits, there are a few things you should consider.

First, changing the Admin setting will not change any existing smart campaigns or email programs. Individual campaigns and programs set to block non-operational emails will still respect communication limits while those set otherwise will still send emails regardless of the limit.
Before you make changes to your admin settings, review all existing email assets. Check that all the appropriate emails are set to operational—and those that shouldn’t be, are not. If reviewing the setting of every email asset in your instance sounds daunting, contact us for a custom script that will capture the settings programmatically via REST API.
Next, do the same with all smart campaigns and email programs. New campaigns and programs created after the change will inherit the global setting, but any clones of existing campaigns will inherit the local setting. This make it essential to check the settings of your program templates. Most, if not all, should be checked to block non-operational sends if email communication limits have been reached. Again, we like to employ REST API and custom scripts to automate the inventory.