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ashah123
Level 4
February 19, 2026
Question

Removing Duplicates Before Sharing Marketing Counts

  • February 19, 2026
  • 1 reply
  • 32 views

Hi Team,

I wanted to confirm the best approach for sharing audience counts with stakeholders before an email launch.

Our subscription lists contain multiple contacts with the same email address. While Marketo automatically handles duplicates at the time of send, we want to report the accurate unique email count in advance. For example, if a list has 50,000 records and 2,500 duplicate email addresses, the actual send count would be 47,500.

Currently, I’m exporting the list and removing duplicates manually in Excel, but I’m looking for a way to get the unique email count directly within Marketo. I tried using the “Duplicate Fields by Email Address” filter, but it returns all records associated with duplicates, not the net duplicate count.

Could you please suggest the most efficient way to get the unique email count in Marketo with minimal manual effort?

Thanks,
Akshat

 

 

1 reply

SanfordWhiteman
SanfordWhiteman
Level 10
February 19, 2026

Unfortunately, there’s no way to do this. 

 

You can create a Smart List just of people with at least one duplicate and check the count, but that will only tell you the absolute maximum number of records (i.e. Smart List count / 2). If some of the email addresses appear in 3+ records the true count will be lower.

 

I’d say this is a good reason to start a duplicate cleanup effort ASAP! When 2+ records with the same email address qualify for the same campaign, that wreaks havoc on reporting. (This isn’t the case if duplicate records are separated via other properties.)

A
ashah123Author
Level 4
February 19, 2026

​@SanfordWhiteman 

Just checking if the screenshot I shared above is the one you meant. It shows all duplicate records, not the unique duplicate count.

For example, if there are 2,000 contacts with 1 duplicates email for each, Marketo shows all 4,000 records, which makes it hard to get the actual duplicate count.

Is there a way to get only the unique duplicate number? 

The last option I see is downloading the Excel and manually calculating it. Even if there’s no direct way in Marketo, any workaround to get close to the unique duplicate count would help.

I’ll also check with our data team, but since we’re a B2B company, many accounts use the same email address for different contacts within the same company, which makes it a bit challenging to manage.

Just wanted to understand—how would these duplicates impact our reporting?

You can create a Smart List just of people with at least one duplicate and check the count, but that will only tell you the absolute maximum number of records (i.e. Smart List count / 2). If some of the email addresses appear in 3+ records the true count will be lower.

 

SanfordWhiteman
SanfordWhiteman
Level 10
February 19, 2026

As I said, a Smart List with the filter Duplicate Fields shows you the people with at least one duplicate.

 

If everyone in the list has exactly one duplicate, then there’s count / 2 unique addresses. For every person in the list that has more than one duplicate, the unique count goes down by (number of duplicates - 1). 

 

Either way, there’s no way to show the unique count within the Marketo UI. If you had a mandatory process that ensured people had only 0 or 1 duplicate (never more than one) it makes the calculation easy, but it’s still not going to be shown in the UI explicitly.

 

You could also use the REST API to pull the Smart List members, dedupe the members on email, and send an alert with the true count. Obviously dev work involved.

 

Seems to me that if the business is concerned about dupes affecting send counts yet won’t take action to fix dupes, there’s a bit of an impedance mismatch.

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