Re-uploading a list into Marketo

[Anonymous]

Hello Marketo Community!

I am still learning how Marketo works and just recently made the mistake of re-uploading a list that had been used for an email send from the previous week. I understand by doing this that dupilicate contacts can be created and bigger problems can occur.

Could someone offer a solution on how to fix this problem?

Additionally, could someone share some insight on why a previously uploaded list should never be reuploaded into Marketo? I'm trying to get some context on my error.

Thank you!

-Megan

[Grégoire_Miche2]

Hi Megan

I understand by doing this that dupilicate contacts can be created and bigger problems can occur

No, this is not true. Marketo does not create duplicates on list upload. It deduplicates based on the email address (or any custom duplicate rule you might have set through Support).

if you have a situation where some duplicates where created, the problem is elsewhere. Typically, duplicate come from the CRM or from a ill-designed API connection.

-Greg