BayMail Pro

From HammerTap:

BayMail Pro is a complete eBay email solution. Send email to other eBay users without their actual email addresses - BayMail Pro can send messages directly to other bidders and sellers using only their eBay IDs. Send messages to large lists of many eBay users at once. Automatically retrieve lists of user IDs from the auction pages on eBay. Save message templates, an address book, and custom mailing lists. Let BayMail Pro manage all your eBay communications! It will evan automatically update itself from the Internet when a new version is available.