X0306 4 2019-03-07 0 0000855612 ZIX CORP ZIXI 0001488288 Miller Maribess L 2711 N. HASKELL AVENUE SUITE 2200 DALLAS TX 75204 1 0 0 0 Deferred Stock Units 2019-03-07 4 A 0 9231 0.00 A 36436 D Deferred Stock Units 2019-03-07 4 A 0 13653 0.00 A 50089 D Deferred Stock Units 2018-02-26 4 D 0 13653 0.00 D Common Stock 13653 45408 D Grant under the 2018 Omnibus Incentive Plan (the "Plan"). The deferred stock units will vest pro-rata and quarterly over one year, and subject to acceleration under conditions described in the Plan. Delivery of the underlying shares in respect of vesting will occur pursuant to the underlying award agreement. On the Form 4/A filed on August 23, 2018, the reporting person elected to report on Table II 13,653 Deferred Stock Units ("DSUs") granted under the Amended and Restated 2012 Incentive Plan. Pursuant to guidance from the Securities and Exchange Commission, the reporting person has now elected to report these DSUs on Table I instead of Table II since the DSUs may be settled solely by delivery of an equal number of shares of the issuer's common stock. Therefore, the reporting person has moved the reporting of these 13,653 DSUs from Table II to Table I. Each deferred stock unit represents a contingent right to receive one share of ZIXI common stock. /s/ Noah F. Webster, Attorney-in-Fact 2019-03-11