After Uploading Results to your MailChimp account and creating segments for 'Indeterminate' and 'Accepts All' categories, you can send campaigns to your subscribers based on these categories. The Safe Segment is automatically created upon purchase.
We do not recommend sending to the 'Accepts-All' segment. We recommend that you attempt a re-engagement campaign to emails with an Email Assurance Grade of B, and if any addresses in your 'Accepts-All' category are determined to be valid, you can then trickle them back into your Safe list very slowly!
We do not recommend sending to the 'Indeterminate' segment ever. You should create a segment for all emails with an Email Assurance Grade of D - but you should not deploy to them.
To deploy a campaign to the Safe segment, go to the Campaigns tab on the left-hand side of your MailChimp Dashboard. Here you can create a new campaign, or replicate an old one, and send to an entire list or a segment. "Send to a Saved Segment" to send only to the Safe list.