- 1 -

 
beyond a period of 10 business days immediately after notice thereof by the Company toEmployee;     (c) The intentional wrongdoing by Employee that is materially injurious to the Companyor employing Affiliate, as applicable; or     (d) Acts by Employee of moral turpitude that are injurious to the Company.     For purposes of this definition, no act, or failure to act, on the part of Employee shall bedeemed to be “intentional” unless done, or omitted to be done, by Employee not in good faith andwithout reasonable belief that Employee’s action or omission was in the best interests of theCompany or the employing Affiliate, or both, as applicable.     1.4 Change in Control. A “Change in Control” of the Company shall have occurred if atany time during the term of this Agreement any of the following events shall occur:     (a) The Company is merged, consolidated or reorganized into or with another corporationor other legal person, other than an Affiliate, and as a result of such merger, consolidationor reorganization less than 50.1’% of the combined voting power to elect directors of thethen-outstanding securities of the remaining corporation or legal person or its ultimateparent immediately after such transaction is owned, directly or indirectly, in the aggregateby persons who were shareholders, directly or indirectly, of the Company immediately prior tosuch merger, consolidation, or reorganization;     (b) The Company sells all or substantially all of its assets to any other corporation orother legal person, other than an Affiliate, and as a result of such sale, less than 50.1% ofthe combined voting power to elect directors of the then-outstanding securities of suchcorporation or legal person or its ultimate parent immediately after such transaction isowned, directly or indirectly, in the aggregate by persons who were shareholders, directly orindirectly, of the Company immediately prior to such sale;     (c) Any Acquiring Person has become the beneficial owner (as the term “beneficial owner”is defined under Rule 13d-3 or any successor rule or regulation promulgated under the ExchangeAct) of securities which when added to any securities already owned by such person wouldrepresent in the aggregate 35% or more of the then-outstanding securities of the Company whichare entitled to vote to elect directors;     (d) If, at any time, the Continuing Directors then serving on the Board of Directors ofthe Company (“Board”) cease for any reason to constitute at least a majority thereof;     (e) Any occurrence that would be required to be reported in response to Item 6(e) ofSchedule 14A of Regulation 14A or any successor rule or regulation promulgated under theExchange Act; or     (f) Such other events that cause a change in control of the Company, as determined by theBoard in its sole discretion.
- 2 -

 
     1.5 Change in Control Payments. “Change in Control Payments” shall mean six months ofbase salary utilizing the higher of (i) Employee’s annual base salary in effect on the date of theChange in Control or (ii) Employee’s highest annual base salary during the term of Employee’semployment with the Company.     1.6 Continuing Director. A “Continuing Director” shall mean a director of the Companywho (i) is not an Acquiring Person, an Affiliate or Associate, a representative of an AcquiringPerson or nominated for election by an Acquiring Person, and (ii) was either a member of ‘the Boardon the date of this Agreement or subsequently became a director of the Company and whose initialelection or initial nomination for election by the Company’s shareholders was approved by amajority of the Continuing Directors then on the Board.     1.7 Good Reason. “Good Reason” shall mean the occurrence of the following event:     (a) a cumulative reduction of more than 10% based on Employee’s highest annual basesalary during the term of Employee’s employment with the Company.EXAMPLE: Assume Employee’s base salary is $100,000. The Company orAffiliate, as applicable, is permitted to reduce Employee’s base salary by up to 10%($10,000) without giving Employee “Good Reason” to terminate employment. Any furthersalary reductions would constitute “Good Reason” to terminate employment. Assumethat in the example, that the Company or Affiliate had reduced the $100,000 salaryto $92,000. Later, the Employee is given a new salary of $120,000. The Company orAffiliate is then entitled to reduce the $120,000 salary by up to $12,000 withoutentitling Employee to “Good Reason”, even though the earlier lower salary had beenreduced by $8,000.     1.8 Person. A “Person” shall mean an individual, a corporation, a partnership, anassociation, a joint stock company, a trust, an incorporated organization or a government orpolitical subdivision thereof.     1.9 Severance Payment. The “Severance Payment” shall be an amount equal to six monthsof base salary utilizing Employee’s highest annual base salary during the term of Employee’semployment with the Company; provided that, if the event giving rise to the Severance Paymentoccurs on or before the 180th day following a Change in Control (with the day immediately followingthe day of the occurrence of the Change in Control being day “1”), then the amount of the SeverancePayment shall be the amount provided for in Sections 1.5 and 3 (as if Employee had resigned fromemployment pursuant to Section 3).2. Severance Payment.     2.1 From and after the date hereof, upon the occurrence of either of the following events, theCompany will pay to Employee the Severance Payment (in accordance with Section 4):     (a) Employee’s employment with the Company or an Affiliate, as applicable, isterminated by the Company or the employing Affiliate other than for Cause; or
- 3 -

 
     (b) Employee terminates his employment for Good Reason, subject to the notice and cureprovisions noted below.     Notwithstanding the preceding provisions, Employee shall not be permitted to resignemployment for a Good Reason until (i) Employee has provided to the Company notice of the existenceof the good reason condition within 90 days of its initial existence, and (ii) the Company has notremedied the good reason condition within a period of 30 days from the Company’s receipt of suchnotice. Following the satisfaction of (i) and (ii), Employee must exercise his right to resign forGood Reason within 30 days (i.e., such Good Reason resignation must occur within 150 days of theoccurrence of the good reason event), with the day immediately following the existence of the goodreason condition being day “1.”     2.2 To terminate Employee’s employment other than for Cause pursuant to Subsection 2,1(a), theCompany or the employing Affiliate, as applicable, shall give Employee a written notice oftermination setting forth in reasonable detail the facts and circumstances claimed to provide abasis for termination of Employee’s employment. Such notice shall be effective 30 days followingthe Employee’s receipt thereof.3. Change in Control Payment. If Employee resigns from employment (subject to the noticeand cure provisions noted below) with the Company and its Affiliates following a Change in Controlfor a “Change in Control Good Reason,” as such term is defined below, the Company shall pay toEmployee the Change in Control Payment (in accordance with Section 4).     A “Change in Control Good Reason” shall mean (i) a material diminution in Employee’sauthority, duties or responsibilities, (ii) a material diminution in the Employee’s base salary,(iii) a material change in the geographic location at which Employee must perform services, (iv) amaterial diminution in the authority, duties, or responsibilities of the supervisor to whomEmployee is required to report, including a requirement that Employee report to a corporate officeror employee instead of the board of directors (or similar governing body), (v) a materialdiminution in the budget over which Employee retains authority, or (vi) any other event thatconstitutes a material breach by the Company of the agreement under which Employee providesservices.     Notwithstanding the preceding provisions, Employee shall not be permitted to resignemployment for a “Change in Control Good Reason” until (a) Employee has provided to the Companynotice of the existence of the good reason condition within 90 days of its initial existence and(b) the Company has not remedied the good reason condition within a period of 30 days from theCompany’s receipt of such notice. Following the satisfaction of (i) and (ii), Employee mustexercise his right to resign for Change in Control Good Reason within 60 days (i.e., such Change inControl Good Reason resignation must occur within 180 days of the occurrence of the good reasonevent), with the day immediately following the existence of the good reason condition being day“1.”4. Mode of Payment; Acceptance. The Severance Payment and the Change in Control Paymentshall be paid in a lump sum (less applicable withholdings for taxes and other withholdings requiredby applicable law) within 60 days following the occurrence of the applicable event, subject to theCompany’s receipt of a release in a form reasonably satisfactory
- 4 -

 
to the Company relating to employment matters. The Company will provide the form release toEmployee within 5 days of the date of the event giving rise to the payment. In the event thatEmployee fails to execute such release within such 60 day time period, he shall forfeit theSeverance Payment or Change in Control Payment, as applicable. The Company’s obligation to pay theSeverance Payment and Change in Control Payment is absolute and such payments shall not bemitigated or offset by virtue of Employee obtaining new employment or failing to seek newemployment. Acceptance by Employee of the Severance Payment or Change in Control Payment, asapplicable, shall constitute a release by Employee of the Company and its Affiliates, shareholders,officers, employees, directors and other agents from all claims arising out of, relating to, or inconnection with, Employee’s employment with, or separation from employment with, the Company andits Affiliates.     Employee shall be entitled to receive pursuant to this Agreement only one of the SeverancePayment or the Change in Control Payment (i.e., not more than one of any such payments is payablepursuant to this Agreement).5. Miscellaneous.     5.1 Dispute Resolution. Employee and the Company acknowledge that Employee has, ormay have, previously executed a Mutual Alternate Dispute Resolution Agreement. The provisions ofsuch Mutual Alternate Dispute Resolution Agreement shall govern any disputes arising under thisAgreement.     5.2 Confidential Information. Employee and the Company acknowledge that Employee haspreviously executed a Confidentiality and Invention Agreement which is incorporated herein byreference and shall survive Employee’s separation from employment in accordance with its terms.     5.3 Notice. All notices and other communications provided for in this Agreement shallbe in writing and shall be deemed to have been received on the date delivered, if personallydelivered, or the date received after being mailed by United States registered or certified mail,return receipt requested, postage prepaid, addressed to the applicable party at the address forsuch party set forth below or at such other address as such party may designate by like notice:       Employee:         David J. Robertson       The Company:         Zix Corporation    2711 North Haskell Avenue, Suite 2200, LB 36    Dallas, Texas 75204-2960    Attn: CEO
- 5 -

 
     5.4 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 following a Changein Control. This Agreement and all rights of Employees hereunder shall inure to the benefit of andbe enforceable by Employee’s personal or legal representatives, executors, administrators,successors, heirs, distributes, devisees and legatees.     5.5. Entire Agreement; Modifications. This Agreement does not supersede anyemployment agreement, stock option agreement or other employment-related agreement (collectively,“Employment Related Agreements”} that may be in effect at the time this Agreement is executed. Anyconflict between the terms and conditions of this Agreement and other such Employment-RelatedAgreements will be resolved on an item-by-item basis with the Employee choosing which agreementcontrols the conflicting issue. Only an instrument in writing executed by both parties may amendthis Agreement. No waiver by either party hereto of, or compliance with, any condition or provisionof this Agreement to be performed by such other party shall be deemed a waiver of similar ordissimilar provisions or conditions at the same or at any prior or subsequent time.     5.6 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.     5.7 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.     5.8 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).     5.9 409A Compliance. This Agreement, as amended, is intended to be exempt from and/orcomply with the requirements (and not otherwise be subject to the interest and penalty taxes of)section 409A of the Internal Revenue Code of 1986, as amended (the “Code”) and the regulations andother guidance issued thereunder, and shall be interpreted in a manner consistent with that intent.Notwithstanding the foregoing, in the event there is a failure under this Agreement to comply withsection 409A of the Code, the Company shall have the discretion to accelerate any payment hereunderof “nonqualified deferred compensation” (within the meaning of section 409A of the Code), but onlyto the extent of the amount required to be included in income as a result of such failure.
- 6 -

 
     IN WITNESS WHEREOF, the parties have executed this Agreement effective on the date and yearfirst above written.         **ZIX CORPORATION**           By: /s/ Susan K. Conner — CFO for Richard D. Spurr      Chairman & CEO           Date: 12-31-08                  **EMPLOYEE**           /s/ David J. Robertson         David J. Robertson           31 Dec, 2008       
- 7 -