Exhibit 99.1 DRIVING GROWTH AND PROFITABILITY IN CLOUD-BASED SOFTWARE AND ADVERTISING I N V E S T O R P R E S E N T A T I O N ▪ O C T O B E R 2 0 1 8 Contains proprietary and confidential information owned by Synacor, Inc. © / 2018 Synacor, Inc. 1 1Exhibit 99.1 DRIVING GROWTH AND PROFITABILITY IN CLOUD-BASED SOFTWARE AND ADVERTISING I N V E S T O R P R E S E N T A T I O N ▪ O C T O B E R 2 0 1 8 Contains proprietary and confidential information owned by Synacor, Inc. © / 2018 Synacor, Inc. 1 1

SAFE HARBOR Safe Harbor statement under the Private Securities Litigation Reform Act of 1995: This presentation contains forward-looking statements concerning Synacor’s expected financial performance as well as Synacor’s strategic and operational plans. The achievement or success of the matters covered by such forward-looking statements involves risks, uncertainties and assumptions. If any such risks or uncertainties materialize or if any of the assumptions prove incorrect, the company's results could differ materially from the results expressed or implied by the forward-looking statements the company makes. Synacor is under no obligation to, and expressly disclaims any such obligation to, update or alter forward-looking statements, whether as a result of new information, future events, or otherwise. The risks and uncertainties referred to above include - but are not limited to - risks associated with: execution of Synacor’s plans and strategies; the loss of a significant customer; the company’s ability to obtain new customers; expectations regarding consumer taste and user adoption of applications and solutions; developments in Internet browser software and search advertising technologies; developments in display advertising technologies and practices; general economic conditions; expectations regarding the company's ability to timely expand the breadth of services and products or introduction of new services and products; consolidation within the cable and telecommunications industries; changes in the competitive dynamics in the market for online search and display advertising; the risk that security measures could be breached and unauthorized access to subscriber data could be obtained; potential third party intellectual property infringement claims; and the price volatility of Synacor’s common stock. Further information on these and other factors that could affect the company's financial results is included in filings it makes with the Securities and Exchange Commission from time to time, including the section entitled Risk Factors in the company's most recent Form 10-K filed with the SEC. These documents are available on the SEC Filings section of the Investor Information section of the company's website at investor.synacor.com. 2SAFE HARBOR Safe Harbor statement under the Private Securities Litigation Reform Act of 1995: This presentation contains forward-looking statements concerning Synacor’s expected financial performance as well as Synacor’s strategic and operational plans. The achievement or success of the matters covered by such forward-looking statements involves risks, uncertainties and assumptions. If any such risks or uncertainties materialize or if any of the assumptions prove incorrect, the company's results could differ materially from the results expressed or implied by the forward-looking statements the company makes. Synacor is under no obligation to, and expressly disclaims any such obligation to, update or alter forward-looking statements, whether as a result of new information, future events, or otherwise. The risks and uncertainties referred to above include - but are not limited to - risks associated with: execution of Synacor’s plans and strategies; the loss of a significant customer; the company’s ability to obtain new customers; expectations regarding consumer taste and user adoption of applications and solutions; developments in Internet browser software and search advertising technologies; developments in display advertising technologies and practices; general economic conditions; expectations regarding the company's ability to timely expand the breadth of services and products or introduction of new services and products; consolidation within the cable and telecommunications industries; changes in the competitive dynamics in the market for online search and display advertising; the risk that security measures could be breached and unauthorized access to subscriber data could be obtained; potential third party intellectual property infringement claims; and the price volatility of Synacor’s common stock. Further information on these and other factors that could affect the company's financial results is included in filings it makes with the Securities and Exchange Commission from time to time, including the section entitled Risk Factors in the company's most recent Form 10-K filed with the SEC. These documents are available on the SEC Filings section of the Investor Information section of the company's website at investor.synacor.com. 2

INVESTMENT HIGHLIGHTS Tech Platform with Multiple Profitable Growth Avenues HIGH-MARGIN TRACK RECORD OF FOCUS ON COST ADVERTISING BUSINESS RECURRING-REVENUE DOUBLE-DIGIT REVENUE REDUCTIONS TO IMPROVE DRIVES CUSTOMER VALUE SOFTWARE BUSINESS GROWTH FOR THREE PROFITABILITY AND REACH YEARS 3 3INVESTMENT HIGHLIGHTS Tech Platform with Multiple Profitable Growth Avenues HIGH-MARGIN TRACK RECORD OF FOCUS ON COST ADVERTISING BUSINESS RECURRING-REVENUE DOUBLE-DIGIT REVENUE REDUCTIONS TO IMPROVE DRIVES CUSTOMER VALUE SOFTWARE BUSINESS GROWTH FOR THREE PROFITABILITY AND REACH YEARS 3 3

SYNACOR BY THE NUMBERS: SOFTWARE BUSINESS DRIVING RECURRING REVENUE GROWTH TTM Revenue (As of June 30, 2018) Q2 ‘18 Q2 ‘18 Non-recurring Recurring Revenue³ Revenue $151.1M Software Revenue = $47.8M $9M $3.8M Software¹ = $12.8M Advertising Revenue = $103.3M 12.9% YoY 17.2% YoY Q2 Software Revenue $35.9M Q2 Total Market Value (As of September 25, 2018) $2M $21.1M Advertising² Market Cap = $66.8M 0% YoY 17.3% YoY Enterprise Value = $51.8M Cash = $15.0M* *As of June 30, 2018 1: Includes licensed and cloud-based Zimbra email and Collaboration, and Identity Management; 2: Includes advanced = $11M portals, publisher advertising, and value-added services; 3: Q2 Recurring Includes public and private cloud-based revenue, Software-as- a-service, subscription licenses, and maintenance Revenue 4 4 4SYNACOR BY THE NUMBERS: SOFTWARE BUSINESS DRIVING RECURRING REVENUE GROWTH TTM Revenue (As of June 30, 2018) Q2 ‘18 Q2 ‘18 Non-recurring Recurring Revenue³ Revenue $151.1M Software Revenue = $47.8M $9M $3.8M Software¹ = $12.8M Advertising Revenue = $103.3M 12.9% YoY 17.2% YoY Q2 Software Revenue $35.9M Q2 Total Market Value (As of September 25, 2018) $2M $21.1M Advertising² Market Cap = $66.8M 0% YoY 17.3% YoY Enterprise Value = $51.8M Cash = $15.0M* *As of June 30, 2018 1: Includes licensed and cloud-based Zimbra email and Collaboration, and Identity Management; 2: Includes advanced = $11M portals, publisher advertising, and value-added services; 3: Q2 Recurring Includes public and private cloud-based revenue, Software-as- a-service, subscription licenses, and maintenance Revenue 4 4 4

TWO GROWING SOURCES OF REVENUE SOFTWARE ADVERTISING Software-as-a-Service, Service Revenue, Search and Advertising, Subscription and Perpetual Licensing Value-added Sales and Services Email/Collaboration Identity Management Advanced Portal Advertising Solutions for Platform Platform Experiences Publishers 5TWO GROWING SOURCES OF REVENUE SOFTWARE ADVERTISING Software-as-a-Service, Service Revenue, Search and Advertising, Subscription and Perpetual Licensing Value-added Sales and Services Email/Collaboration Identity Management Advanced Portal Advertising Solutions for Platform Platform Experiences Publishers 5

PROVEN TRACK RECORD OF STRONG GROWTH ANNUAL REVENUE $151.1* $ MILLIONS $140.0 $127.4 $110.2 2015 2016 2017 TTM *Trailing 12 months (TTM) calculated as of June 30, 2018. 6PROVEN TRACK RECORD OF STRONG GROWTH ANNUAL REVENUE $151.1* $ MILLIONS $140.0 $127.4 $110.2 2015 2016 2017 TTM *Trailing 12 months (TTM) calculated as of June 30, 2018. 6

COST REDUCTIONS DRIVING IMPROVED Total Expected PROFITABILITY Annualized Savings • Q1 2018 cost reductions: $4M annualized savings • Closing of Toronto office $8M • Headcount and contractor reductions Adjusted EBITDA • Data center consolidation (process underway; (2017) savings in 2019 and 2020) $2.3M • Q2 2018 cost reductions: $4M annualized savings • Closing of San Francisco office Adjusted EBITDA TTM (as of June 30, 2018) • 30 additional positions eliminated • Committed to balancing profitability with disciplined $7.2M investments in revenue growth 7 7COST REDUCTIONS DRIVING IMPROVED Total Expected PROFITABILITY Annualized Savings • Q1 2018 cost reductions: $4M annualized savings • Closing of Toronto office $8M • Headcount and contractor reductions Adjusted EBITDA • Data center consolidation (process underway; (2017) savings in 2019 and 2020) $2.3M • Q2 2018 cost reductions: $4M annualized savings • Closing of San Francisco office Adjusted EBITDA TTM (as of June 30, 2018) • 30 additional positions eliminated • Committed to balancing profitability with disciplined $7.2M investments in revenue growth 7 7

ENGAGING TECH PLATFORM ADVERTISING SOFTWARE EMAIL & IDENTITY MANAGEMENT ADVANCED PORTAL ADVERTISING SOLUTIONS FOR COLLABORATION PLATFORM PLATFORM EXPERIENCES PUBLISHERS 8ENGAGING TECH PLATFORM ADVERTISING SOFTWARE EMAIL & IDENTITY MANAGEMENT ADVANCED PORTAL ADVERTISING SOLUTIONS FOR COLLABORATION PLATFORM PLATFORM EXPERIENCES PUBLISHERS 8

Worldwide Business Email SOFTWARE OPPORTUNITY 2017-2020, CAGR User Growth User Growth 19% 4% • Value Proposition includes open-source software, competitive pricing, security and privacy, local Identity as a Service Revenue Growth 2017-2022, CAGR partner networks, and scalability 37% • Continue to drive innovation, e.g. Blockchain-enabled secure email; persistent authentication Synacor Q2 Software Revenue • Grow partner community and accelerate email $12.8M 14% customer growth Software Customer Q2 • Grow penetration of ID Management among video Acquisition & Retention operator and content provider customers $ Retention Rate >100% • Extend ID Management into new verticals and geographies New Customers Booked Total Customers 110 4,300 Source: Radicati Group; Technavio, September 2017-22 9 9Worldwide Business Email SOFTWARE OPPORTUNITY 2017-2020, CAGR User Growth User Growth 19% 4% • Value Proposition includes open-source software, competitive pricing, security and privacy, local Identity as a Service Revenue Growth 2017-2022, CAGR partner networks, and scalability 37% • Continue to drive innovation, e.g. Blockchain-enabled secure email; persistent authentication Synacor Q2 Software Revenue • Grow partner community and accelerate email $12.8M 14% customer growth Software Customer Q2 • Grow penetration of ID Management among video Acquisition & Retention operator and content provider customers $ Retention Rate >100% • Extend ID Management into new verticals and geographies New Customers Booked Total Customers 110 4,300 Source: Radicati Group; Technavio, September 2017-22 9 9

ZIMBRA X ON BLOCKCHAIN Blockchain Industry Revenue 2022, $B • Blockchain is a decentralized, incorruptible digital ledger. Many analysts believe the Blockchain technology market could grow to over $7B $7B+ • Significant optionality for Synacor in nascent Blockchain market through Zimbra X, which was built from the ground up to be a container-based, cloud- native product that can powerfully leverage Blockchain technology • Zimbra X is the first Enterprise Decentralized App powered by EOSIO, a leading Blockchain platform • Zimbra X Beta powered by EOSIO, which leverages Blockchain capabilities such as smart contracts and EOS Tokens – affirming Zimbra’s position as the collaboration choice for businesses on Blockchain Source: Market & Research; Zion Market Research 10 10ZIMBRA X ON BLOCKCHAIN Blockchain Industry Revenue 2022, $B • Blockchain is a decentralized, incorruptible digital ledger. Many analysts believe the Blockchain technology market could grow to over $7B $7B+ • Significant optionality for Synacor in nascent Blockchain market through Zimbra X, which was built from the ground up to be a container-based, cloud- native product that can powerfully leverage Blockchain technology • Zimbra X is the first Enterprise Decentralized App powered by EOSIO, a leading Blockchain platform • Zimbra X Beta powered by EOSIO, which leverages Blockchain capabilities such as smart contracts and EOS Tokens – affirming Zimbra’s position as the collaboration choice for businesses on Blockchain Source: Market & Research; Zion Market Research 10 10

SEARCH & ADVERTISING OPPORTUNITIES Synacor Media Ad Platform at Scale • Value proposition includes white labeling, platform as a service, scalability, and innovative business model monetized through advertising • Building user engagement by leveraging video, 35M+ Hundreds 200M mobile and data Households of Publishers Uniques • Winning new portal customers • Growing publisher reach and launching new ad Digital Ad Spending Revenue Growth 2017-2020, CAGR products • Portal services, including platform and user migration, product development and 14% customization, site hosting and operations, and deep systems integration creates significant customer “stickiness” Source: eMarketer, growth for 2017 – 2020 11 11SEARCH & ADVERTISING OPPORTUNITIES Synacor Media Ad Platform at Scale • Value proposition includes white labeling, platform as a service, scalability, and innovative business model monetized through advertising • Building user engagement by leveraging video, 35M+ Hundreds 200M mobile and data Households of Publishers Uniques • Winning new portal customers • Growing publisher reach and launching new ad Digital Ad Spending Revenue Growth 2017-2020, CAGR products • Portal services, including platform and user migration, product development and 14% customization, site hosting and operations, and deep systems integration creates significant customer “stickiness” Source: eMarketer, growth for 2017 – 2020 11 11

AT&T CONTRACT UPDATE • Synacor provides white-label portal and advertising services for the att.net platform as part of a three-year agreement: • 12-month migration away from former vendor • Innovative desktop and mobile portal services that drive user engagement • Sourcing rich Internet content from popular brands • Monetizing experiences through search and advertising • Current deal had been set to renew on March 28, 2019 • AT&T requested negotiations on new agreement and sent non-renewal notice on August 24, 2018 to avoid automatic renewal • Synacor and AT&T negotiations on new agreement currently underway 12 12AT&T CONTRACT UPDATE • Synacor provides white-label portal and advertising services for the att.net platform as part of a three-year agreement: • 12-month migration away from former vendor • Innovative desktop and mobile portal services that drive user engagement • Sourcing rich Internet content from popular brands • Monetizing experiences through search and advertising • Current deal had been set to renew on March 28, 2019 • AT&T requested negotiations on new agreement and sent non-renewal notice on August 24, 2018 to avoid automatic renewal • Synacor and AT&T negotiations on new agreement currently underway 12 12

ENVIABLE CUSTOMER REACH Over 100 Operator and Content Provider Customers, More than 4,000 Enterprise and Government Customers, Hundreds of Publisher Customers, Over 1,900 Channel Partners Operator and Content Provider Customers Enterprise Customers Command and Simulation Solutions Chile Indonesia Partners 13ENVIABLE CUSTOMER REACH Over 100 Operator and Content Provider Customers, More than 4,000 Enterprise and Government Customers, Hundreds of Publisher Customers, Over 1,900 Channel Partners Operator and Content Provider Customers Enterprise Customers Command and Simulation Solutions Chile Indonesia Partners 13

INVESTMENT HIGHLIGHTS Tech Platform with Multiple Profitable Growth Avenues HIGH-MARGIN TRACK RECORD OF FOCUS ON COST ADVERTISING BUSINESS RECURRING-REVENUE DOUBLE-DIGIT REVENUE REDUCTIONS TO IMPROVE DRIVES CUSTOMER VALUE SOFTWARE BUSINESS GROWTH FOR THREE PROFITABILITY AND REACH YEARS 14 14INVESTMENT HIGHLIGHTS Tech Platform with Multiple Profitable Growth Avenues HIGH-MARGIN TRACK RECORD OF FOCUS ON COST ADVERTISING BUSINESS RECURRING-REVENUE DOUBLE-DIGIT REVENUE REDUCTIONS TO IMPROVE DRIVES CUSTOMER VALUE SOFTWARE BUSINESS GROWTH FOR THREE PROFITABILITY AND REACH YEARS 14 14

THANK YOU 15THANK YOU 15

APPENDIX 16APPENDIX 16

ADJUSTED EBITDA RECONCILIATION 2016 2017 2018 Q1 Q2 Q3 Q4 FY'16 Q1 Q2 Q3 Q4 FY'17 Q1 Q2 Revenue $ 30,260 $ 30,476 $ 31,721 $ 34,916 $127,373 $ 26,540 $31,216 $ 36,269 $ 46,002 $140,027 $32,915 $35,923 Net (loss) / income $(1,565) $(2,757) $(3,365) $(3,053) $(10,740) $(6,656) $(3,276) $ 261 $ (106) $ (9,777) $(2,375) $(2,584) Provision for income taxes 144 260 379 436 1,219 446 309 244 101 1,100 20 293 Interest expense 68 84 75 91 318 87 114 127 105 433 97 88 Gain on sale of investment — — — — — — — (1,902) (85) (1,987) — --- Other expense (2) (242) 38 248 42 (6) (67) (99) 174 2 (119) 133 Depreciation and amortization 2,098 2,270 2,414 2,453 9,235 2,184 2,224 2,596 2,816 9,820 2,435 2,444 Capitalized software impairment — — — 334 334 — 256 — — 256 — --- Stock-based compensation expense 737 687 680 667 2,771 647 676 605 562 2,490 553 537 Restructuring costs — — — — — — — — — — — 268 Adjusted EBITDA $ 1,480 $ 302 $ 221 $ 1,176 $ 3,179 $(3,298) $ 236 $ 1,832 $ 3,567 $ 2,337 $ 611 $1,179 17ADJUSTED EBITDA RECONCILIATION 2016 2017 2018 Q1 Q2 Q3 Q4 FY'16 Q1 Q2 Q3 Q4 FY'17 Q1 Q2 Revenue $ 30,260 $ 30,476 $ 31,721 $ 34,916 $127,373 $ 26,540 $31,216 $ 36,269 $ 46,002 $140,027 $32,915 $35,923 Net (loss) / income $(1,565) $(2,757) $(3,365) $(3,053) $(10,740) $(6,656) $(3,276) $ 261 $ (106) $ (9,777) $(2,375) $(2,584) Provision for income taxes 144 260 379 436 1,219 446 309 244 101 1,100 20 293 Interest expense 68 84 75 91 318 87 114 127 105 433 97 88 Gain on sale of investment — — — — — — — (1,902) (85) (1,987) — --- Other expense (2) (242) 38 248 42 (6) (67) (99) 174 2 (119) 133 Depreciation and amortization 2,098 2,270 2,414 2,453 9,235 2,184 2,224 2,596 2,816 9,820 2,435 2,444 Capitalized software impairment — — — 334 334 — 256 — — 256 — --- Stock-based compensation expense 737 687 680 667 2,771 647 676 605 562 2,490 553 537 Restructuring costs — — — — — — — — — — — 268 Adjusted EBITDA $ 1,480 $ 302 $ 221 $ 1,176 $ 3,179 $(3,298) $ 236 $ 1,832 $ 3,567 $ 2,337 $ 611 $1,179 17