The ZixCorp Software incorporates compression code by the Info-ZIP group. There are no extra charges or costs due to the use of this code, and the original compression sources are freely available from CompuServe in the IBMPRO forum and by anonymous ftp from the Internet site ftp.uu.net/pub/archiving/zip/. We will also, upon request, mail our customers the full sources to the compression code that we use on a 3.5" MSDOS-format diskette (or other appropriate medium) for the cost of mailing. Send U.S. $10.00 to the address noted in 'Contact Us', Attention: Legal Department, and reference "Request for Info-ZIP source code."

Hash functions used in the ZixCorp Software are derived from the RSA Data Security, Inc., MD-5 Message-Digest Algorithms.

The ZixCorp Software incorporates spell-checking code form The Sentry Spelling-Checker Engine, copyright (c) 1999 WintertreeSoftware, Inc.

Some of the processes, arrangements, user interfaces, transaction sequences, site and system architectures, data arrangements, and data processing algorithms, described or embodied in our products and services, may be covered by one or more of the following U.S. Patents Nos. 5,790,790; 6,061,448 and 6,192,407 owned by Tumbleweed Communications Corp. ZixCorp holds a license to these patents.