Feeding the Durable Unsubscribe List without increasing the database

One common question is how can we add a list of emails to the durable unsubscribed list, coming for instance from other systems, without increasing the size of the Marketo database. This is a key requirement as soon as you use other systems than Marketo to send emails and want to keep complying with legal requirements.

This getting even more complex if one has to manage the fact that some of these leads already exist in the Marketo database and should be kept there, together with their historical information.

The idea is to create a simple program that will handle this efficiently and automatically. Here are the components of the program :


  1. Let start with the "DurableUnsubscribed Import" list : This is where the durable unsubscribed will be imported. Once the process is finished as we will see, the list will be empty.
  2. The "Durable Unsubscribed Deletion List" will contain all the leads that are unsubscribed but should not be kept in the database. In other words, they were added to Marketo when you imported leads to the Durable Unsubscribe Import list. It's filters are set as is :
    • Please note the usage of the "lead was created" filter with a "List Name" constraint : it enables you to detect specifically the leads that were added only to be added to the DUL.
    • We combine this with a "member of list" filter that also checks during the process that the lead is still a member of the import list. As the lead deletion will occur after 2 hours, it enables you to change your mind and remove a lead from the list.
  3. The smart campaign that does the job is a triggered one
    • It will fire when the lead is added to the list
    • As it is not allowed to change the "unsubscribe" field through an import, we need to handle it in the smart campaign flow :
      Then we wait 2 hours to leave Marketo ample time to log the un-subscription (We can even leave it 1 day, but do not make it too short). After this delay, we check the lead is still there, waiting for deletion and has been created during the import. For this, we check the lead still belong the the "Durable Unsubscribed Deletion List" smart list and, if so, we delete it.Finally, if the lead has not been deleted (meaning it was there already and is supposed to have some history in the database), we remove it from the Import List

Alternatively, we can set the smart campaign as a batch and run it manually after completing an import in the Import List. In this case, we would replace the trigger with the  following filter :

This process will also work if you use the import list API calls and import them to the "Durable Unsubscribe Import" List :

Do not hesitate to provide feedback and alternatives, I'll incorporate them.


Level 10 - Champion Alumni

His process assumes these records are synced in Marketo to SFDC. If they are not, then it may not be necessary to "delete in SFDC" as well.

I'm curious why you would see dupes in SFDC if you uploaded the list in Marketo? Were they already deleted and you synced them back?

Level 2

Hi Josh,

I set "Remove from SFDC" to false for my flow step.

The lead lifecycle picked up the durable unsubscribed import records as net new, and synced them all to SFDC. The campaign Smart List is a trigger for "Person is Created and source type is not" - I'm thinking I could add "is not List Import" as well to avoid the duplication? Appreciate any advice!


Level 10


Yes, you should exclude all members of this list from the LLC campaigns.

The easiest to do this is to add a FILTER to your trigger LLC campaign:

member of list NOT IN durable unsubscribe import list.


Level 2

Hey guys,

A stupid question - do the unsubscribed leads (not the deleted ones) count to your contacts cap? That is - do you really need to delete the unsubs every so often in order to keep the database count under the cap?

Level 10 - Community Moderator

Unsubscribed leads still count.  Remember that you can still use them for other purposes besides email.

Level 2

Thank you Sanford!

Level 10 - Community Moderator

it seems that Marketo is blocking that new person from even being created

What do you mean by "it seems"?

There's no such restriction, so you'll have to explain the symptoms more.

Level 10 - Community Moderator

This isn't the best place for ongoing discussion so let's please consolidate under Delete Person Flow Step - Can this person be imported again?