If your growth plan starts with "we will buy a list of 50k industry contacts," you do not have a growth plan. You have an account suspension waiting to happen.
Every reputable email platform — Inbox OSS, SendGrid, Mailgun, Postmark, all of them — prohibits sending to purchased lists. We monitor for the signals (spike in complaints, hits on known spam-trap addresses, sudden volume from a new domain) and suspend accounts that show the pattern.
The reason is not corporate politics. Purchased lists destroy sender reputation. Even if your platform tolerated it, your inbox placement would crater within hours.
What works instead: a content magnet on your site that captures email + explicit consent, a partner co-marketing webinar, a paid acquisition channel that drives sign-ups. Slower, but every name on the list is a name that asked to be there.