I have an old email list that's slowly been getting new sign-ups, a few a day. Over the past ten years it's got like 15,000 people on the list but it's also been ten years since I've used it. I'm launching a rebrand and want this old list to know about it. Since it's so old I'm afraid some of the people on it will think I'm spamming them. Of course I have no idea how many of these are real and valid emails as well.
Can your tool:
1. help filter a list that hasn't been used for ten years and make sure that even legit people end up not complaining about it as spam since it has been used forever. Or at least offer advice on how to approach this?
2. Can your tool it validate 15,000 emails?
3. If I need to validate 15,000 emails, what tier should I get?

Thank you!