When a registered shopper comments 'SOLD' on an item, then this auto-reply confirms their order and links to the customer's account page for the shopper to check out.
This auto-reply prompts new customers without an email address on their account to log in and add their email address. This auto-reply notifies shoppers when a waitlisted item is back in stock and informs them how to pay and when their cart expires. If an item is sold out when a shopper attempts to purchase it, then this auto-reply notifies them that they've been added to the waitlist. If a shopper does not properly format a SOLD comment (e.g., missing a variant), then this auto-reply prompts the shopper to repost their comment with the correct variant.
