Need Help Sending Emails to a few big lists

Hi there. I'm about to have a bunch of emails scraped from websites that match businesses I make SaaS software for. I need help sending out a one time email to those businesses. I'm not sure the best way to do this. I'm hoping to have 10,000 emails and I'm ok if we have to break up the list into smaller groups of emails. I just want to know the best way to do this.

Thanks!