Those messages containing "Your eBay Item Sold!" are not pulled in through eBay's GetMemberMessages API, but by configuring your POP/IMAP account associated with your eBay store to read in ReplyManager, you are now able to pull in those emails and route them to the appropriate folder.
If managing these emails is an important part of your daily workflow, here are a few steps to route those messages properly:
Step 1: Go to Maintenance > Folders, Add New Folder.
Folder Name Suggestion: eBay - Items Sold
Step 2: Go to Maintenance > Accounts, Add New Account
Configure your POP or IMAP account associated with your eBay account
Step 3: Go to Maintenance > Rules, Add New Rule
Apply the rule to the appropriate POP or IMAP account
NOTE: If you already have your POP or IMAP account configured in ReplyManager, be sure to set the ranking for this rule higher than your eBay duplicates rule.