EXHIBIT 10.31**SEVERANCE AGREEMENT**     THIS SEVERANCE AGREEMENT (this “Agreement”), entered into as of November 10, 2006, is made andentered into between Zix Corporation, a Texas corporation (the “Company”), and Barry W. Wilson(“Employee”).     WHEREAS, Employee is currently employed by the Company;     WHEREAS, Employee is willing to continue working for the Company or a Company affiliate(“Affiliate”), as applicable, on an “at-will” basis;     NOW, THEREFORE, in consideration of the foregoing and of the respective covenants andagreements of the parties herein contained, the parties agree as follows:1. Severance Payment. If the Employee’s employment with the Company or an Affiliate, asapplicable, is terminated by the Company or the employing Affiliate prior to the second anniversaryof the date of this Agreement other than “for cause” (as defined below), then, subject toreceiving a release reasonably satisfactory to the Company relating to employment matters, theCompany will pay to Employee an amount equal to six months of base salary, using Employee’s highestmonthly base salary during the term of Employee’s employment (the “Severance Payment”). TheSeverance Payment will be paid as provided in Section 2. To terminate Employee’s employment otherthan “for cause,” the Company or the employing Affiliate, as applicable, shall give Employee awritten notice of termination setting forth in reasonable detail the facts and circumstancesclaimed to provide a basis for termination of Employee’s employment. Such notice shall beeffective upon receipt. For purposes of this Severance Agreement, “for cause” shall mean any ofthe following shall have occurred: (a) the conviction of Employee of any felony; (b) theintentional and continued failure by Employee to substantially perform Employee’s employmentduties, such intentional action involving willful and deliberate malfeasance or gross negligence inthe performance of Employee’s duties (other than any such failure resulting from Employee’sincapacity due to physical or mental illness), after written demand for substantial performance isdelivered by the Company or an Affiliate, as applicable, that specifically identifies the manner inwhich the Company or the Affiliate, as applicable, believes Employee has not substantiallyperformed Employee’s duties and that is not cured within five business days after notice thereof bythe Company to Employee; (c) the intentional wrongdoing by Employee that is materially injurious tothe Company or employing Affiliate, as applicable; (d) acts by Employee of moral turpitude that areinjurious to the Company or employing Affiliate, as applicable; or (e) breach of the“confidentiality and invention” agreement between the Company or an Affiliate, as applicable, andEmployee.2. Mode of Payment; Acceptance. The Severance Payment shall be paid in six equal monthlycash payments (less applicable withholdings for taxes and other withholdings required by applicablelaw and any amounts owed by Employee to Company or an Affiliate, as applicable) within 30 days ofthe occurrence of the applicable event. Alternatively, the Company may, in the Company’sdiscretion, pay the Severance Payment by depositing in the Employee’s stock brokerage accountregistered shares of ZixCorp common stock valued at 104% of the Severance Payment, using the
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closing price of the ZixCorp common stock on the business day of deposit. The Company’s obligationto pay the Severance Payment is absolute, and such payments shall not be mitigated or offset byvirtue of Employee obtaining new employment or failing to seek new employment. Acceptance byEmployee of the Severance Payment shall constitute a release by Employee of the Company and itsAffiliates, shareholders, officers, employees, directors and other agents from all claims arisingout of, relating to, or in connection with Employee’s employment with the Company.3. Miscellaneous.     3.1 Dispute Resolution. Employee and the Company acknowledge that Employee has, ormay have, previously executed an alternate dispute resolution agreement with the Company or anAffiliate. The provisions of such alternate dispute resolution agreement shall govern any disputesarising under this Agreement.     3.2 Successors; Binding Agreement. This Agreement will be binding upon and inure tothe benefit of the parties hereto and any successors in interest to the Company. This Agreementand all rights of Employees hereunder shall inure to the benefit of and be enforceable byEmployee’s personal or legal representatives, executors, administrators, successors, heirs,distributes, devisees and legatees.     3.3. Entire Agreement; Modifications. This Agreement represents the entire agreementof the parties relating to the subject matter hereof. Only an instrument in writing executed byboth parties may amend this Agreement. No waiver by either party hereto of, or compliance with,any condition or provision of this Agreement to be performed by such other party shall be deemed awaiver of similar or dissimilar provisions or conditions at the same or at any prior or subsequenttime.     3.4 Validity. The invalidity or unenforceability of any provision or provisions ofthis Agreement shall not affect the validity or enforceability of any other provision of thisAgreement, which shall remain in full force and effect.     3.5 Enforcement Fees. In the event of a dispute arising under this Agreement, unlessotherwise agreed by the parties in writing, each party shall pay its own costs and expenses inresolving the dispute.     3.6 Governing Law. This Agreement shall be governed by and construed in accordancewith the laws of the State of Texas (excluding its conflict of laws rules).     IN WITNESS WHEREOF, the parties have executed this Agreement effective on the date and yearfirst above written.
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       **ZIX CORPORATION**            By: /s/ Richard D. Spurr          Richard D. Spurr    Chairman and Chief Executive Officer       **EMPLOYEE**       /s/ Barry W. Wilson      Barry W. Wilson
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