Exhibit 99.1   Press Release | For Distribution

Zix Reports First Quarter 2020 Financial Results

Cross-Selling Efforts Drive 15% Organic Revenue Growth to $52.4 Million, Coupled with Improving Profitability Demonstrating Business Model Resiliency

DALLAS — May 6, 2020 — Zix Corporation (Zix) (NASDAQ: ZIXI), a leading provider of cloud email security solutions, today announced financial results for the first quarter ended March 31, 2020.

First Quarter 2020 Financial Highlights (results compared to the same year-ago quarter)

Recent Operational and Product Highlights

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		Exhibit 99.1   Press Release | For Distribution

Management Commentary

“Our stable financial performance and uninterrupted operational execution in the first quarter is a testament to our team’s unwavering commitment to helping our customers and partners meet the challenges of today’s remote work environment,” said David Wagner, Zix’s Chief Executive Officer. “The COVID-19 pandemic is accelerating digital transformation and is increasing the need for robust business communications solutions that ensure organizations remain secure, compliant and productive. Our launch of Secure Cloud offers a new, secure modern workplace solution to empower our customers and partners to deliver business value in the digital workplace. It also embodies the complete integration of Zix and AppRiver, bringing together the best of our technologies to enable users to collaborate securely and productively across a broad range of communication channels and locations; capabilities that are essential in today’s remote work environment.

“Internally, we are focused on employee safety and our dedicated team is delivering for partners and customers to ensure the long-term health and viability of our business. Our 100% subscription business delivers essential productivity, security and compliance solutions to a diversified customer base with a concentration in the healthcare and financial services industries where our solutions are critical. However, we know that we are not immune to the current market dynamic. Many of our customers, especially our smaller customers, are struggling with decreased demand. As a result, we are focused on balancing profitability as we capitalize on the positive market momentum for digital transformation. We are confident in our long-term vision of growth through taking additional market share, facilitating the successful transition of our customer base to Secure Cloud, and operating our organization as efficiently as possible. Our success today will better position Zix in a post-COVID-19 environment and enable the realization of our vision to be the leading provider of cloud email security, compliance and productivity solutions for companies of all sizes.”

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		Exhibit 99.1   Press Release | For Distribution

Zix’s Chief Financial Officer Dave Rockvam added: “We delivered on our revenue and EPS guidance for the quarter, demonstrating the resiliency of our business model and our focus on delivering profitable adjusted EBITDA growth on an absolute basis. We were also encouraged by our continued success within productivity, and we ended the quarter in a solid and durable liquidity position with $16.3 million in cash and $17 million available through our revolving credit facility. Additionally, the $9 million of annualized costs we recently took out of our business, along with our strong free cash flow generation and adjusted EBITDA outlook, provide us with enough cushion on our leverage ratio to meet our debt obligations. We have a plan and foundation in place to ensure we can navigate these uncertain times, and we believe that our industry-leading solutions, proven strategy and world-class team will enable us to capitalize on the digital transformation opportunity that’s already underway.”

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		Exhibit 99.1   Press Release | For Distribution

Financial Outlook

Zix provides guidance based on current market conditions and expectations. The company emphasizes that the guidance is subject to various important cautionary factors referenced in the section entitled “Forward-Looking Statements” below, including risks and uncertainties associated with the COVID-19 pandemic.

For the second quarter of 2020, the company forecasts revenue to range between $52.0 million and $53.0 million, which implies a 10% to 12% organic growth rate compared to the same year-ago quarter. The company forecasts fully diluted GAAP earnings (loss) per share (attributable to common stockholders) to be in the range of ($0.07) and ($0.06) and fully diluted non-GAAP adjusted earnings per share (attributable to common stockholders) before deemed dividends and excluding deferred tax (benefit) expense to be in the range of $0.12 and $0.14 for the second quarter of 2020. The company forecasts adjusted EBITDA to be approximately 23% to 25% of forecast revenue for Q2 2020. The per share guidance figures are based on an approximate basic share count of 53.7 million for Q2 2020.

Based on management’s current visibility, the company has updated its revenue range for the full fiscal year of 2020 to reflect the currently anticipated impact of the COVID-19 pandemic on its operations. The company now forecasts revenue to range between $210 million and $217 million, representing an increase of between 21% and 25% compared to fiscal year 2019 and between 9% and 13% on an organic basis. The company also expects fully diluted GAAP earnings (loss) per share (attributable to common stockholders) to range between ($0.13) and ($0.09) and fully diluted non-GAAP adjusted earnings per share (attributable to common stockholders) before deemed dividends and excluding deferred tax (benefit) expense to be $0.56 to $0.58 for fiscal year 2020. The company forecasts adjusted EBITDA to be in the range of $51.0 million and $53.0 million (or 23% to 25% of forecast revenue) for 2020, representing a year-over-year increase of between 29% and 34% compared to fiscal year 2019. The per share figures are based on an approximate basic share count of 54.0 million for 2020. The company is withdrawing its full year 2020 Annual Recurring Revenue (ARR) forecast due to the current market conditions and uncertainties related to the ongoing COVID-19 pandemic.

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		Exhibit 99.1   Press Release | For Distribution

Conference Call Information

Management will discuss these financial results and outlook on a conference call today (May 6, 2020) at 5:00 p.m. ET (2:00 p.m. PT).

A live webcast of the conference call will be available in the investor relations section of Zix’s website here. Alternatively, participants can access the conference call by dialing 1-855-853-6940 (U.S. toll-free) or 1-720-634-2906 (international) at least 15 minutes before the call and entering access code 9997693. If you have any difficulty connecting with the conference call, please contact Gateway Investor Relations at 1-949-574-3860.

An audio replay of the conference will be available for seven days by dialing 1-855-859-2056 (U.S. toll-free) or 1-404-537-3406 (international) and entering the access code 9997693. An archive of the webcast will also be available on the Zix investor relations website.

About Zix Corporation

Zix Corporation (Zix) is a leader in email security. Trusted by the nation’s most influential institutions in healthcare, finance and government, Zix delivers a superior experience and easy-to-use solutions for email encryption and data loss prevention, advanced threat protection, unified information archiving and bring your own device (BYOD) mobile security. Focusing on the protection of business communication, Zix enables its customers to better secure data and meet compliance needs. Zix is publicly traded on the Nasdaq Global Market under the symbol ZIXI. For more information, visit www.zixcorp.com.

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Forward-Looking Statements

As more fully described in Zix’s Quarterly Report on Form 10-Q for the quarter ended March 31, 2020, which is expected to be filed with the SEC on May 11, 2020, the company has been actively monitoring the COVID-19 situation and its impact on both the company and the world in which we operate. The impact of COVID-19 and unprecedented measures to prevent its spread are affecting our business in various ways such as causing volatility in demand for our products, changes in customer behavior, including their spending and payment patterns, disruptions in the operations of our third party suppliers and business partners, and limitations on our employees’ ability to work and travel. We expect the ultimate significance of the impact on our financial and

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		Exhibit 99.1   Press Release | For Distribution

operational results will be dictated by the length of time that these circumstances continue, which will depend on the currently unknowable extent and duration of the COVID-19 pandemic and governmental and public actions taken in response. These factors also make it more challenging for management to estimate the future performance of our business, particularly over the near term.

Statements in this release that are not purely historical facts or that necessarily depend upon future events, including statements about forecasts of sales, revenue, annual recurring revenue, EBITDA, EBITDA margin, earnings or earnings per share, potential benefits of acquisitions and strategic relationships, or other statements about anticipations, beliefs, expectations, hopes, intentions or strategies for the future, may be forward-looking statements within the meaning of Section 21E of the Securities Exchange Act of 1934, as amended. Readers are cautioned not to place undue reliance on forward-looking statements. All forward-looking statements are based upon information available to Zix on the date this release was issued. Zix undertakes no obligation to publicly update or revise any forward-looking statements, whether as a result of new information, future events or otherwise. Any forward-looking statements involve risks and uncertainties that could cause actual events or results to differ materially from the events or results described in the forward-looking statements, including but not limited to risks or uncertainties related to the completion and integration of acquisitions, the effects of our debt and equity financing transactions, year-end adjustments to previously reported preliminary unaudited financial information, market acceptance of both existing and new Zix solutions, changing market dynamics resulting from technological change, innovation and continuing customer migration to the cloud, changes in the competitive ecosystem, how privacy and data security laws may affect demand for Zix data protection solutions, and business disruptions, uncertainty and market instability stemming from the COVID-19 pandemic and governmental actions related thereto. Zix may not succeed in addressing these and other risks. Further information regarding factors that could affect Zix’s business and its financial and other results can be found in the risk factors section of Zix’s most recent annual report on Form 10-K and quarterly report on Form 10-Q, each as filed with the Securities and Exchange Commission, as those risk factors may be supplemented in subsequent filings.

We monitor ARR as an operating metric, which we define as the aggregate annualized contract value attributable to recurring revenue contracts as of the end of the applicable reporting period. We calculate ARR by determining the annual or monthly revenue of subscription agreements that are active as of the end of the applicable period and multiplying by 1 or 12. We monitor this metric to aid in determining to what extent individual customer relationships, considered in the aggregate, are growing or declining in financial magnitude. ARR is an operating metric derived as of the date of determination, and should be viewed independently of revenue, unearned revenue and any other GAAP financial measure over any period.

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This presentation includes Non-GAAP measures. Our Non-GAAP measures, including “Non-GAAP adjusted net income and net income per share excluding deferred tax expense” are not meant to be considered in isolation or as a substitute for comparable GAAP measures and should be read only in conjunction with our consolidated financial statements prepared in accordance with GAAP. For a detailed explanation of the adjustments made to comparable GAAP measures, the reasons why management uses these measures, the usefulness of these measures and the material limitations of these measures, see Notes to Reconciliation of GAAP to Non-GAAP Financial Measures on the next page.

This presentation includes Non-GAAP measures. Our Non-GAAP measures, including “Non-GAAP adjusted net income per share excluding deferred tax expense” are not meant to be considered in isolation or as a substitute for comparable GAAP measures and should be read only in conjunction with our consolidated financial statements prepared in accordance with GAAP. For a detailed explanation of the adjustments made to comparable GAAP measures, the reasons why management uses these measures, the usefulness of these measures and the material limitations of these measures, see Notes to Reconciliation of GAAP to Non-GAAP Financial Measures on the next page.

ZIX CORPORATION

NOTES TO RECONCILIATION OF GAAP TO NON-GAAP FINANCIAL MEASURES

USE OF NON-GAAP FINANCIAL INFORMATION

The Company occasionally utilizes financial measures and terms not calculated in accordance with generally accepted accounting principles in the United States (“GAAP”) in order to provide investors with an alternative method for assessing our operating results in a manner that enables investors to more thoroughly evaluate our current performance as compared to past performance. We also believe these Non-GAAP measures provide investors with a more informed baseline for modeling the Company’s future financial performance. Management uses these Non-GAAP financial measures to make operational and investment decisions, to evaluate the Company’s performance, to forecast and to determine compensation. Further, management utilizes these performance measures for purposes of comparison with its business plan and individual operating budgets and allocation of resources. We believe that our investors should have access to, and that we are obligated to provide, the same set of tools that we use in analyzing our results. These Non-GAAP measures should be considered in addition to results prepared in accordance with GAAP, but should not be considered a substitute for or superior to GAAP results. We have provided definitions below for certain Non-GAAP financial measures, together with an explanation of why management uses these measures and why management believes that these Non-GAAP financial measures are useful to investors. In addition, in our earnings release we have provided tables to reconcile the Non-GAAP financial measures utilized to GAAP financial measures.

ADJUSTED NON-GAAP MEASURES

Our Non-GAAP measures adjust GAAP Cost of revenue, Gross profit, Research and development expense, Selling and marketing expense, General and administrative expense, Operating income, Net income, Net Income excluding deferred tax (benefit) expense, Net income per share—diluted, Net income per share—diluted excluding deferred tax (benefit) expense, and EBITDA for non-cash stock-based compensation expense, and strategic consulting and litigation costs to derive Non-GAAP adjusted Cost of revenue, adjusted Gross profit, adjusted Research and development expense, adjusted Selling and marketing expense, adjusted General and administrative expense, adjusted Operating income, adjusted Net income, adjusted Net income per share—diluted and adjusted EBITDA. We provide a reconciliation of these adjusted Non-GAAP measures to GAAP Gross profit, Operating income, Net income, Net income per share—diluted and EBITDA.

Our forward-looking adjusted Non-GAAP earnings per share information consistently excludes non-cash stock-based compensation expense. Additionally, the adjusted Non-GAAP earnings per share will consistently exclude litigation expenses and non-recurring items that impact our ongoing business. See items (A) through (E) below for further information on the current quarter’s reconciling items.

Items (A) through (F) on the “Reconciliation of GAAP to Non-GAAP Financial Measures” table are listed to the right of certain categories under “Gross profit,” “Operating income,” “Net income,” “Net income excluding deferred tax (benefit) expense,” “Net income per share—diluted,” “Net income per share excluding deferred tax (benefit) expense- diluted,” and “EBITDA” and correspond to the categories explained in further detail below under (A) through (F).

(A) Non-cash stock-based compensation charges relating to stock option grants, restricted stock, and restricted stock units awarded to and accounted for in accordance with Share-Based Payment accounting guidance. See (1) on previous page for breakdown of stock-based compensation. Because of varying valuation methodologies, subjective assumptions and varying award types, the Company believes that the exclusion of stock-based compensation charges provides for more accurate comparisons to our peer companies and for a more accurate comparison of our financial results to previous periods. Additionally, the Company believes it is useful to investors to understand the specific impact of non-cash stock-based compensation charges on our operating results.

(B) Strategic consulting, acquisition integration and litigation costs. See item (2) on previous page. The Company’s management excludes certain board-directed consulting costs and litigation expenses when evaluating its ongoing performance and/or predicting its earnings trends and therefore excludes these charges on our adjusted operating results.

(C) Intangible amortization costs. See item (3) on previous page. The Company’s management excludes amortization expenses associated with the acquisition of intangible assets when evaluating its ongoing performance and/or predicting its earnings trends and therefore excludes these charges on our adjusted operating results.

(D) Corporate separation payment relating to employment termination benefits agreement. See item (4) on previous page. The Company’s management excludes these costs when evaluating its ongoing performance and/or predicting its earnings trends and therefore excludes these charges on our adjusted operating results.

(E) Deferred tax expense represents the non-cash tax expense included in the GAAP tax provision, including the current period utilization of deferred tax assets created in previous periods. The remaining provision for income taxes represents expected cash taxes to be paid.

(F) EBITDA represents earnings before interest, taxes, depreciation and amortization. Adjusted EBITDA adds back stock-based compensation charges and litigation expenses.