When I send a mass emailer out, I receve thousands of email alerts that a new lead has been created in Marketo for me... How can these be stopped? Thanks
The answer to your question is not that simple. You need to look at one of these leads in Marketo and analyze the activity log to see by what smart campaign the alert was sent.
There is something weird, though: sending an email has nothing to do with lead creation, unless something is missing in the process your are describing.
A quick way to do this is to use the "Campaign Inspector" in "Marketing Activities" and search for your email address. It will show all smart campaigns using your email address in the smart list or flow steps and from there you can see which flow has an alert.
If you do not see the "Campaign Inspector" tab, you will need to enable it in Admin > Treasure Chest.