I'm trying to create a new Contact List from a CSV file of 400.000 contacts. When I upload it and enter the contact list, in the bottom it says the list has only 339.788 contacts. There are many repeated emails, but I checked manually and there are 388.363 unique emails, so even if qualtrics if consolidating them automatically, there are still 48575 missing contacts. Does anyone know what are the possible reasons for these behaviour? Thanks.

Check if you have trimmed emails while uploading. Also it happens due to invalid emails.

Hey @fstram! If you have not yet already, I would recommend reaching out to our Support Team so they can further troubleshoot and escalate if needed!

Missing contacts when creating Contact List

Missing contacts when creating Contact List | Experience Community