   Yahoo! DomainKeys Patent License Agreement v1.2

   Copyright (c) 2006, Yahoo! Inc.
   All rights reserved.

   This Yahoo! DomainKeys Patent License Agreement (this "Agreement") is
   between Yahoo! Inc. ("Yahoo!") and you ("Licensee"). By attempting to
   exercise any rights granted under this Agreement, Licensee agrees to be
   bound by all the terms and conditions set forth below, and subject to those
   terms and conditions, Licensee may use the intellectual property described
   below.

   1. LICENSE GRANT.

   1.1. Subject to the terms and conditions of this Agreement, Licensor hereby
   grants You a royalty-free, perpetual, worldwide, sublicensable,
   non-exclusive license under its rights to the Yahoo! Patent Claims to make,
   use, sell, offer for sale, and/or import Implementations.

   2. DEFINITIONS.

   2.1. "DomainKeys Developer(s)" means Yahoo, Inc. ("Yahoo!"), Licensor,
   and/or any other individual or entity who distributes Implementations under
   this Agreement.

   2.2. "Implementations" means the specific portions of a hardware or
   software implementation expressly required to be compliant with the
   Specifications for the sole purpose of a sender verification solution in
   connection with e-mail.

   2.3. "Licensor" means Yahoo! or any other individual or entity that elects
   to use this Agreement to license Yahoo! Patent Claims to any licensee.

   2.4. "Specifications" means the specification having submission ID
   "draft-delany-domainkeys-base-01.txt" dated Aug 2004 published through the
   IETF (Internet Engineering Task Force). The Specifications may be found at
   the following link:
   http://antispam.yahoo.com/domainkeys/draft-delany-domainkeys-base-01.txt

   2.5. "Yahoo! Patent Claims" shall mean those claims of all Yahoo! foreign
   and domestic patents and patent applications that base their priority on
   U.S. Provisional Patent Application Ser. Nos. 60/497,794, filed Aug. 26,
   2003, or 60/553,300, filed Mar. 15, 2004, or U.S. Patent Application Ser.
   Nos. 10/671,319, filed Sep. 24, 2003, or 10/805,181, filed Mar. 19, 2004.

   2.6. "You" or "Your" means an individual, company, or other legal entity
   exercising any rights under this Agreement. Any individual who accepts the
   terms and conditions of this Agreement on behalf of a company or other
   legal entity represents and warrants that the individual has the authority
   to enter into this Agreement on behalf of the company or other legal
   entity.

   3. TERMS.

   3.1. You agree not to assert against Yahoo!, any other DomainKeys Developer
   or any of their respective licensees under Section 3.4, a patent
   infringement claim based on the manufacture, use, sale, offer for sale
   and/or importation of any Implementations ("Implementation IP Claim").

   3.2. To indicate your assent to the terms and conditions of this Agreement
   and in order to obtain a license to make, use, sell, offer for sale, and/or
   import Implementations, You must include, attach or preserve the following
   prominently displayed statement in the source code and object code of any
   such Implementations: "This code incorporates intellectual property owned
   by Yahoo! and licensed pursuant to the Yahoo! DomainKeys Patent License
   Agreement.".

   3.3. You will not use the name of Yahoo! to endorse or promote any
   products, services, or Implementations without specific prior written
   permission of Yahoo!. "DomainKeys" is a trademark of Yahoo!. However, You
   may state Your Implementations are "DomainKeys compliant", "supports
   DomainKeys", or is "DomainKeys-enabled", without citation to Yahoo!. You
   must create Your own product or service names or trademarks for Your
   Implementations and You agree not to use the term "DomainKeys" in or as
   part of a name or trademark for Your Implementations.

   3.4. You may choose to distribute Implementations under this Agreement or a
   different agreement, provided that:

     (a) a copy of this Agreement or the different agreement is included with
     each Implementation along with the following prominently displayed
     statement: "By making, using, selling, offering for sale, importing,
     and/or sublicensing Implementations as permitted, you agree to the terms
     and conditions of the Yahoo! DomainKeys Patent License Agreement or
     other agreement contained herein."; and

     (b) if distributed under a different agreement, such different agreement
     contains terms and conditions that (i) provide no fewer rights,
     privileges and immunities to DomainKeys Developers than the terms and
     conditions of this Agreement, including, without limitation, Sections
     1.1, 3.1, 3.4, 3.7, 4.1, 4.2, and 4.3.

   3.5. You acknowledge that implementations of the Specifications may be
   subject to U.S. export restriction and other applicable national and
   international laws. You agree to comply with all export, re-export, or
   import restrictions, laws, or regulations.

   3.6. Yahoo!, and only Yahoo!, may, from time to time and at its sole
   discretion, update or modify the terms of this Agreement. If Yahoo! makes
   any such modifications, You may continue under the terms and conditions of
   this Agreement or agree to the updated or modified terms and conditions.
   For the most recent version of this Agreement please contact Yahoo!.

   3.7. This Agreement and the rights hereunder will terminate:

     (a) automatically without notice from Yahoo!, if You at any time during
     the term of this Agreement assert any Implementation IP Claim against
     Yahoo!;

     (b) upon written notice from Yahoo!, if You at any time during the term
     of this Agreement assert any Implementation IP Claim against any
     DomainKeys Developer (other than Yahoo!) or any licensees of any
     DomainKeys Developer; or

     (c) where (a) or (b) do not apply, automatically without notice from
     Yahoo!, if You fail to comply with any term(s) of this Agreement and
     fail to cure such breach within 30 days of You becoming aware of such
     breach.

   3.8. This Agreement constitutes the entire agreement between the parties
   with respect to the subject matter hereof. This Agreement shall be governed
   by and construed under the laws of the United States and the State of
   California without giving effect to California conflict of law provisions
   or to construction provisions favoring either party. All actions arising
   out of or relating to this Agreement that involve Yahoo! as a party will be
   adjudicated exclusively by the Superior Court of the State of California
   for the County of Santa Clara or the United States District Court for the
   Northern District of California.

   3.9. In the event that any provision of this Agreement is deemed to be
   invalid, such invalidity shall not affect the remainder of this Agreement.

   4. LEGAL DISCLAIMERS.

   4.1. THE YAHOO! PATENT CLAIMS, THIS AGREEMENT, THE DOMAINKEYS TRADEMARK,
   AND THE SPECIFICATIONS ARE PROVIDED ON AN "AS IS" BASIS, WITHOUT
   REPRESENTATIONS, WARRANTIES OR CONDITIONS OF ANY KIND, EITHER EXPRESS OR
   IMPLIED, INCLUDING, WITHOUT LIMITATION, ANY REPRESENTATIONS, WARRANTIES OR
   CONDITIONS OF TITLE, NON-INFRINGEMENT, MERCHANTABILITY, OR FITNESS FOR A
   PARTICULAR PURPOSE. You are solely responsible for determining the
   appropriateness of exercising any rights under this Agreement and using the
   Specifications and the DomainKeys trademark and assume all risks associated
   in connection therewith, including, but not limited to, the risks and costs
   of program errors, compliance with applicable laws, damage to or loss of
   data, programs or equipment, and unavailability or interruption of
   operations.

   4.2. You expressly acknowledge and agree that no assurances are provided by
   DomainKeys Developers with respect to the validity of the Yahoo! Patent
   Claims or that the Specifications, the DomainKeys trademark or any
   implementations related to the Specifications or the DomainKeys trademark
   do not infringe or misappropriate the patent, trademark or other
   intellectual property rights of any other entity. DomainKeys Developers
   disclaim any liability to You for claims brought by any other person or
   entity based on infringement or misappropriation of intellectual property
   rights or otherwise. As a condition to exercising the rights and licenses
   granted hereunder, You hereby assume sole responsibility to secure any
   other intellectual property rights needed.

   4.3. DOMAINKEYS DEVELOPERS SHALL NOT HAVE ANY LIABILITY FOR ANY DIRECT,
   INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
   (INCLUDING WITHOUT LIMITATION LOST PROFITS), HOWEVER CAUSED AND ON ANY
   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE EXERCISE
   OF ANY RIGHTS UNDER THIS AGREEMENT, EVEN IF ADVISED OF THE POSSIBILITY OF
   SUCH DAMAGES, AND EVEN IF THE REMEDIES PROVIDED FOR IN THIS AGREEMENT FAIL
   OF THEIR ESSENTIAL PURPOSE.
