Once your auction is completed, you can process the payments.
In Workspace > Auctions > Auctions:
You can select one record to process.
Or, you can filter the grid to process one constituent; check off the checkout box(es) and click Checkout.
In Workspace > Auctions > Bid History:
Click Actions > Process Bids to process all winning bids. Bids will be charged to the donor's credit card.
Note: In Auctions > Auctions you can suppress the Thank You email if you want. Otherwise, the thank you is sent.
In Auctions > Bid History, Actions > Process Bids the Thank You email will be sent if the payment is successful.