Message Partners' MPP multi-platform mail filter and archival system supports SURBLs with MTAs "Postfix, Exim, Sendmail, Qmail, Communigate Pro, Surgemail, Sun Java System Messaging Server and email platforms with a generic SMTP/LMTP filter interface."

http://www.messagepartners.com/mpp-products/

MPP can also support SURBLs through a SpamAssassin interface.