Hey Derrick Sanchez,
It's important that you set up a program to add these leads to, so that you can easily track them by program and List name. Create a list in a Program, then import those leads into that list.
Best practice is to send them the info, your rep wants to send them, with a CTA asking them if they would like to Opt In to your email updates.
For everyone that doesn't opt-in, set them to Marketing Suspended and Unsubscribed for safe measure. If you want to remove them from your database entirely, you then have that list you can pull, and create a Smart Campaign with a Flow Step "Delete Lead".
*If your Marketo instance is synced to SFDC, make sure you are able to keep the leads from entering sales queues before importing the list!* That would be an unfortunate user experience if you take all efforts to keep them from receiving emails, Sales sees them as new prospects, and reaches out to them regardless .
Let me know if this helps!
Thank you for your feedback. We started to do what you are describing, and we do sync SFDC to MKTO. So we assign these one-time leads to a special marketing queue so nobody calls on them.
In general, I do not recommend uploading any non opted in lists, even if it is legal in the US. There are some services that verify and/or verify opt in, that's different and ok usually.
Better to encourage people who care to sign up and be raving fans because they want to hear from you.