Since you’re (or could be) using this same form at multiple places, you should ideally add constraints for the query string and referrer URL too so only people who fill out the form from that specific source (LinkedIn) and campaign (if applicable) could flow through your send email campaign's flow. You also set this up as a trigger campaign-
- Trigger: Fills out Form with Referrer (or Web page if the form is placed on a Marketo LP) and Querystring constraints set
- Filter: Person Was Created with Source constraint as Web form fillout, Form Name = <form>, and Date of Activity in past <few> minutes
- Flow: Wait 7 days and Send Email
You can use advanced wait properties so the person comes out of the wait step on a particular day and time post which they'd be sent the email. Make sure the campaign's schedule tab is configured so a person can only run through the flow once. I don't really like using the Date of Activity constraint, but if you don't use it, the campaign would let people who were created by filling out this form earlier and who filled out this form again qualify which I belive is something you don't want. You can trigger off of the Person is Created trigger as well instead of the Filled out Form added as filter, but there might be a case that by the time the Filled out form activity gets logged in the person’s activity log, the smart campaign would have already processed this person (and rejected as they didn't have Filled out form activity at that point in time).