Hello @TimH394 ,
Please refer to our email permissions policy. If you have permission from a contact for the purpose of sending marketing emails, then you'd be in the clear. If not, you're far more likely to get spam reported or large numbers of unsubscribes - which in turn can hurt sending reputations for you and us, result in account reviews, or outright result in your account being shutdown if the issue is serious enough.
If you're not sure, then it's safest to not consider them contacts that have given you permission. The next step would be confirming them, either by:
importing them and sending a re-confirm opt-in (will place them in Awaiting Confirmation permission),
contacting them outside of our system to confirm, or
encouraging them to use a sign up form you can provide
See also:
Enabling Confirm Opt-In
Review and Compliance FAQ
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