Getting Technical with Marketo Email Sending Methods: Pros, Cons, and What is Best for Your Needs

Not applicable



This blog post exists as a guide to better understand how Marketo sends emails, the various methods in which to send emails, as well as the pros and cons of using certain methods depending on what needs to be accomplished in sending an email. I've posted this in the Markto Summit group to provide a possible guide to those looking to better understand Marketo around the convention.

I created this document while Senior Marketing Automation Specialist at R2integrated; I do not claim full rights of the document, but post it here on the Marketo Community to enrich thought leadership and act as work sample.

Methods of Sending Email in Marketo:

The method used to send an email is all dependent on your email sending needs. Does you need a few different emails sent over a certain period of time but only on certain days? Do you need one email to be sent immediately but only to very specific audience? Does the email need to be sent on a staggered schedule, but only if the recipient engages with a previous piece of email content? These are the types of questions that will need to be answered before setting up an asset to send an email. Without knowing exactly how you need the email to be sent, to whom it will be sent, to whom not to send, as well as what times it should be sent and how frequently; it will be very hard to select the correct sending method.

Single Flow Action Email Send

Likely the easiest method to send a piece of content to a lead in Marketo, the single flow action email send does not require the set up of an asset (program or campaign) to accomplish sending an email.

This method will allow for selecting a single or multiple leads to send an email directly and immediately, in the Lead database. This is a manual method of sending email and is not recommended if the goal is to automate the sending process. It is appropriate to use this method when a single piece of email content needs to be sent out immediately, without need for reporting or status updates.

There are no criteria that can be entered to further specify lead data, but is simply a direct send just as if you were to use a standard email client send like Outlook or Gmail. Here are a few pros and cons of using a Single Flow Action Email Send.


  • Quick, manual send to one or multiple leads
  • Allows for one email to be sent
  • Prevents the Marketing Activities dashboard to be further cluttered by unneeded campaigns or program assets for sending one simple email.
  • Creates backend log of actions taken in case logs need to be pulled for reporting


  • Not an automated method of sending
  • No adjustable campaign criteria to determine lead exclusions or other significant data for sending the email
  • Not easily added to reports

Smart Campaign Email Send:

Smart campaigns can be used to send emails or accomplish many other aspects of the automated marketing lifecycle for leads. For example, not only can emails be sent through the campaigns “Flow” tab, but the leads score can be changed, criteria can be set up to remove a lead from the flow of the campaign or other campaigns, they can be added to lists and just about anything you need to accomplish for your leads can be done in a smart campaign. This, however, can only be accomplished in the ‘flow’ or sending mechanism of the campaign.

Campaigns also have a built in smart list, which allow a user to set up qualifying lead criteria. For example, if you need an email to be sent to only leads who have never engaged with that email before, were a part of a particular past program or campaign, and they had filled out a particular form, the smart list of the campaign can pull in filters to narrow down the criteria for the desired leads. The Flow of the campaign can also have “wait steps” added, staggering the send times of emails or changing of lead data to whenever is necessary.

Smart Campaigns are Marketo’s universal method for getting things done, and also provides a schedule tab which allows for a one time run of the campaign, or schedule out many reoccurrences. This kind of scheduling makes a campaign a “Batch Campaign,” which means leads get processed in batches. Smart Campaign can also be built to be fully automated, using triggers in the smart list. Added a trigger to the smart list changes the campaign into a “Trigger Campaign.” A trigger is a type action activity mechanism which can pull in leads automatically based on certain criteria.

One of the most common triggers used in Marketo is “Filled Out Form” trigger. This trigger, once the campaign is activated, will pull in any new lead that just filled out a particular form on one of your landing pages. There are all sorts of filters and triggers that can be used to pull leads into a campaign. The more automated a campaign can be, the less work for those who build and maintain it.The Smart Campaign also has a minimal reporting dashboard that tells a user the Run History of the campaign, what Emails are being used, what other assets are referencing that campaign in its ‘Used By’ tab, as well as membership stats.

There is lastly a Results tab which allow a user to view leads who have been processed and if they are hitting all of the correct flow steps. There are many pros and cons to using Smart Campaigns. Here are few examples:


  • Freedom to pull in any variation of leads based on criteria for a batch or triggered send.
  • Reporting in campaign
  • Many different options for sending email, based on choices such as ‘send if received other piece of email’
  • Many options for setting new lead criteria within flow
  • Standard and best option for sends for a staggered period of time


  • No detailed reports on email statistics
  • Not an ideal method for sending emails based on particular cadence
  • Will send same email to a lead twice, unless criteria are set up in the schedule to prevent this
  • Not an ideal option for AB testing, though testing is a an option, albeit a difficult setup

Email Program

Email Programs are also a multifaceted method if sending an email and are relatively simple to implement. They have a smart list which allows for lead data criteria to be established which will only bring in particular leads. It has an email selection area that allows for an email to be selected for send. Send times can be established through adjusting the Schedule dashboard, and confirmation can be managed in approval dashboard.Though a Email Program can be used to send out an email, its best put to use when setting up Email A/B tests. The Email Program can perform several types of A/B testing:

  • Subject Line
  • Whole Email
  • From Address
  • Date/Time

These A/B testing methods allow for one email to be utilized with different date/times sent, or different subject lines or from addresses. It also allows a user to test whole emails against each other, selecting several emails for contending. The Email Program has a diverse reporting dashboard that provides statistics on opens, clicks, unsubscribes, click to open ratios as well as engagement summaries.

The program also allows use of program centric “My Tokens” to be used within emails. My Tokens are custom tokens which can be built for the sole purpose of use within the programs assets, such as an email, but not anywhere else in Marketo. The Email Program additionally has a Members tab and Setup Tab, which allow a user to see the leads that are in the program, statuses those leads have achieved, as well as set up criteria for the send. What are the pros and cons of the Email Program?


  • Advanced reporting properties and statistical analysis to the program dashboard
  • Ability to send a single email, quickly and efficiently
  • Many A/B testing options which allow for pulling in multiple emails or a single email and set different appearance criteria such as subject line.
  • Use of “My Tokens” for further customizability for program assets


  • Not an ideal method for sending out multiple emails
  • No cadence or send criteria beyond A/B testing and single time send timeframe
  • Single use setup (not recommended to use more than once)
  • No flow actions to change any other lead criteria, other than send an email

Engagement Program (Nurture Program)

These sort of programs are designed for long term interaction and engagement with your leads. Most of what can be accomplished in an Engagement Program can also be accomplished in a Smart Campaign, however, Engagement Programs allow for sleeker, simpler setup without the use of a complicated, traffic cop style Flow. This method of sending incorporates full automation of email sends.

Engagement Programs allow user to set up a stream of emails based on cadence criteria which will manage when a lead gets email content. For example, if you have 4 different emails to be sent out to your leads who are dropped into the funnel of stream 1, then the cadence can be set to only send out the first email in the stream Mon-Fri at 11am. This can also be adjusted to only send on Tuesdays and Saturdays, any time of day.

There are many different ways a cadence can be adjusted. When a lead goes through a single stream, even if they had received one of the emails in the stream before, it will not receive the email a second time. If a lead is sent email 1 in stream 1 on Monday, then move on to email 2 on Tuesday, but have received email 2 before in a different campaign, that lead will immediately move on to receive email 3 instead. That is unless the availability for that particular email is adjusted to only be available in a certain time frame, such as between the 6th and 11th of that month of the stream send.

When a lead has received all of the email content, that lead will now have “Exhausted Content,” meaning they have no more content to receive and will remain in a hold state in the program until more content is added or transitioned to a new stream. Multiple streams can be set up in an Engagement program. Each stream can have different content, different cadence, and can be meant for only particular leads. Dropping leads into streams is just like dropping a marble the top of a funnel.

As it descends, a user wants it to hit al the right action items before being dropped into the next funnel. There are transition rules which can be set up for an of the streams which can move leads from one stream to another based on any given lead data criteria.Leads can be put in streams via single flow static or smart list action, via smart campaign, or via direct import into the member’s tab of the Engagement program. There is also an engagement dashboard that shows complex statistics of lead engagement with the content you send them.

The program can also use “My Tokens” for its assets as well. Engagement programs are meant to interact with leads over a long period of time; days, weeks, months, even years. It all depends on what your engagement needs are. Not only can emails be added to stream content, but also programs. If the Engagement Program has child asset programs which have campaigns that send out emails based only on certain criteria, the leads can be dropped into those programs via the streams cadence. So what are some of the main pros and cons of this sort of email sending method?


  • Engage with leads over long periods of time
  • Will not send the same piece of content twice
  • Allows for cadence to be set up to interact with leads only at given times
  • Set availability of certain content
  • Use of My Tokens
  • Diverse statically analysis through dashboard
  • Multiple ways to drop leads in stream ‘funnel’
  • Transition rules can be established to change a lead from one stream to another in an automated fashion
  • Can add both emails and programs to stream content


  • Not recommended for one time sends
  • Has to send emails at the same time of day for all emails in a stream
  • Is the most complicated method of sending emails and engaging with leads, but has the highest amount of reporting available
  • No A/B testing as standard setup