X0306 4 2016-02-18 0 0000855612 ZIX CORP ZIXI 0001188811 ROBERTSON DAVE 2711 N. HASKELL AVENUE SUITE 2200, LB 36 DALLAS TX 75204 0 1 0 0 Vice President Common Stock 2016-02-18 4 A 0 40000 0.00 A 161546 D Common Stock 2016-02-19 4 M 0 10807 A 172353 D Common Stock 2016-02-19 4 F 0 3529 3.82 D 168824 D Common Stock 2016-02-20 4 F 0 3265 3.53 D 165559 D Common Stock 2016-02-21 4 F 0 4119 3.53 D 161440 D Restricted Stock Units 2016-02-19 4 M 0 10807 0.00 D Common Stock 10807 26666 D Grant under the Amended and Restated 2012 Incentive Plan (as amended, the "Plan"). The restricted stock ("RS") grant consists of 50% RS that will vest pro rata annually over 3 years and 50% that will vest up to 1/3 each year the company meets approved performance goals in 2016-2018, subject to acceleration under conditions described in the Plan. Each restricted stock unit ("RSU") converts into a share of common stock on a one-for-one basis. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $3.53 to $4.28, inclusive. The reporting person undertakes to provide to Zix Corporation, any security holder of Zix Corporation, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within such range. Granted under the Plan on February 19, 2015. The 40,000 RSU grant consists of 50% RSUs that will vest pro rata over 3 years and 50% that will vest up to 1/3 each year the Company meets approved performance goals in 2015-2017, subject to acceleration under conditions described in the Plan. /s/ Justin K. Ferguson, Attorney-in-Fact 2016-02-22