I have a list of contacts that sign up for our newsletter but I don't want to sync the list members to Salesforce.
I am adding the members as Static List and use that list just for the newsletter in the newsletter program.
Is this right? I want to be more cautious on that because the list is very big with around 5000 emails.
If you think I can do it in some other way please suggest.
Adding these people into a static list is fine. I would make sure though that nothing is going to trigger a "Sync to SFDC" flow. So I would test the import first with a handful of leads to make sure they remain in Marketo and are not synced over to SFDC. I would also check the parent program of the list to make sure it isn't synced with any SFDC campaigns, which would inadvertently sync the people over.