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zix Exhibit 99.1 Press Release | For Distribution Zix Reports First Quarter 2021 Financial Results Continued Strong Adoption of Secure Cloud Platform Drives 14 % Increase in Revenue and ARR , 20 % Growth in Cloud ARR and $ 10.7 million in Cash Flow from Operations DALLAS - May 5 , 2021 - Zix Corporation ( Zix ) ( NASDAQ : ZIXI ) , a leading provider of cloud email security , productivity , and compliance solutions , today announced financial results for the first quarter ended March 31 , 2021 . First Quarter 2021 Financial Highlights ( results compared to the same year - ago quarter ) Revenue increased 14 % to $ 60.0 million . Annual recurring revenue ( ARR ) increased 14 % to $ 243.6 million . Cloud ARR increased 20 % to $ 214.3 million or 88 % of total ARR . GAAP net loss totaled ( $ 2.5 ) million compared to a year ago net loss of ( $ 0.9 ) million . GAAP net loss attributable to common stockholders totaled ( $ 4.8 ) million compared to a year ago net loss attributable to common stockholders of ( $ 3.1 ) million . The company's Q1 2021 net loss attributable to common shareholders includes the effect of a deemed dividend to preferred shareholders of $ 2.3 million and acquisition - related expenses of $ 0.4 million . GAAP fully diluted earnings ( loss ) per share attributable to common stockholders totaled ( $ 0.09 ) compared to ( $ 0.06 ) . Non - GAAP adjusted net income before deemed dividends and excluding deferred tax ( benefit ) expense totaled $ 7.9 million compared to $ 6.7 million . Non - GAAP adjusted net income per share before deemed dividends and excluding deferred tax ( benefit ) expense increased 16 % to $ 0.15 . Adjusted EBITDA increased 18 % or $ 2.0 million to $ 13.1 million , representing an adjusted EBITDA margin of 22 % . The company ended the quarter with $ 23.7 million in cash . Cash flow from operations was $ 10.7 million , an increase of 142 % or $ 6.3 million compared to the prior year period . www.zixcorp.com 1