I know this seems like a dumb question but I've seen evidence of it over and over again.
My mailings seem to go to "bad" leads even after they've been deleted. I will get a bounceback from an email address, go into All Leads and search for it and find that it does not exist.
I've submitted multiple examples to support and their answer was that I can't prove the emails were sent from Marketo, which sounds ridiculous.
Has anyone else experienced this? Any thoughts or suggestions?