SendPlus is a downloadable spam blocker for MS Outlook, Outlook Express, and Eudora. SendPlus employs the challenge response system, which unlike filter-based systems actually determines if the sender of e-mail is a real person. Filter based systems, which are based on rules that are defeated by spammers, often tag valid e-mails as spam and delete them. SendPlus' challenge response system is effective against spam and ensures that valid e-mails always make it to your inbox.

The license of this software is Freeware, you can free download and free use this anti spam software.