Slack CEO Stewart Butterfield made a confession in late September: he admitted email was useful.

Butterfield made the confession at the HubSpot Inbound marketing conference in Boston. His full quote reveals what Butterfield, CEO of a self-professed "email killer" company, truly thinks of email and its future: "Email will probably be with the human species for another 30 to 40,000 years or something like that. It's hard to imagine how it goes away because it's now fulfilling many roles for us. It's a centralized system for resetting all our passwords. It's where all your receipts or transactions go. It's a way for anyone in the world to send anyone else a message. It's very useful."

While not exactly a ringing endorsement of email as a productivity tool, Butterfield’s comment fed into a wider discussion that preceded Slack's move into the enterprise and open challenge to email: what roles do email and social networks fulfill in the workplace? How do workers choose between one and the other? And is pitting the debate as an either/or question missing the point?

Email's Sticking Power

The recent Adobe Consumer Email Survey Report 2017 for the U.S. shows that in spite of progress by social networks, email continues to dominate the workplace.

It also shows email leading as the preferred communication method at work (36 percent), while enterprise social networks are only preferred by one percent of respondents. Survey responders reported spending an average of 3.3 hours per weekday checking work email and 85 percent expected their work email use to increase or stay the same over the next two years.

Perhaps surprisingly, the results also indicated high email usage among millennials. Despite their obsession with social media, texting and chat apps in the workplace, millennials check email more frequently than any other age group. Millennials also expect their use of email to increase over the next two years by a higher percentage than any other age group.

The relatively poor performance of social networks in the survey of 1000 U.S. workers can in part be explained by the length of time it takes for any enterprise tool to catch on. Keep in mind email had a good 45-year head start over Slack if we give Ray Tomlinson credit for sending the first email in 1971.

Different Strokes, Different Folks

However, Jordan Harling, chief digital strategist at UK-based Roman Blinds Direct, a European online seller of window blinds said the figures don’t give the full picture.

Slack is centered around immediacy and collaboration, it’s an instant real-time messaging tool which allows for easy discussion between teams. Messages tend to be short, reactive and encompassing a single idea. Email on the other hand, is a slower, more deliberate medium. There is less expectation for an immediate response which allows for time to craft a more thought-out reply.

"Neither is inherently more useful for business. For fast-paced projects, the constant cooperation and fast paced iteration which Slack allows might be crucial,” he said. “For individual-led projects which require deep thought and concentration, though, it just can’t compare to email. Slack is a magnificent tool, one which we’re certain to see continue to thrive, but it’ll be as a complement to email, not as a replacement.”

Why Slack, Why Email?

We asked a number of companies how they used the two tools and whether they thought Slack would replace email, as Butterfield has claimed in the past. The responses provide some encouragement for supporters of both apps.

Nick Sawinyh, product manager at Santa Monica, Calif.-based SEO specialist Seomator, believes use of either depends on the individuals using them and the company needs. Both have their drawbacks.

“If you have never tried a social media solution like Slack, it's creative and not very complicated. It allows co-workers and collaborators to work together without sending emails back and forth," he said.

“Slack does have a negative side for some and that is no privacy and doing everything out in the open. Although email has its problems, only a percentage of it is real email while the rest are canned responses, notifications, etc. It still allows people to work in privacy. If you have a regular corporate job, Slack may not work for you. It depends on the company and the individual."

Learning Opportunities

Benefits and Concerns

So how is it being used? Scott Bauer is marketing director with Kelowna, British Columbia-based Navigator Multimedia, a web design and digital marketing agency. He said the introduction of Slack in his company notably slashed email clutter.

“We have been using Slack internally for about one year now. Products like Slack today have replaced email for light discussion or the day to day small requests. The response rate is faster, internal email clutter is almost completely gone,” he said. “Workflow efficiency in file sharing and other third party extensions add custom utility to different businesses. I love a future where email didn’t exist, but that will be a very slow transition and there would have to be one messaging app to rule them all rather than Slack, Facebook, Atlassian and other growing workplace messaging sharing the space.”

Industries bound by security and compliance restrictions are not against the use of social networks per se, but still harbor security concerns.

Earl Manguiat is director of information technology at Lyndhurst, NJ-based  law firm Scarinci Hollenbeck. While he said he liked Slack and other social networks, he still had concerns around adoption and information security.

“Although Slack is an innovative and wonderful team-building system, it will likely be years before there is widespread adoption. You will always need traditional means of communication in business (e.g., Outlook), because even though it’s 2017, there are still many end users who are tech-resistant (particularly in certain professional services settings),” he said. “Secondly, Slack (like many cloud-based systems) is frequently hacked and therefore more vulnerable. The security breaches have added to the uncertainty re: adopting that platform. There are plenty of third-party providers who can secure email, but none that can secure Slack or similar programs.”

Tried But True: Face to Face Collaboration

Antoinette Forth, co-founder and CEO of Tampa, Fla.-based Walkabout Collaborative said that from a productivity perspective, at least two fundamental problems will ensure Slack and email exist side by side.

Firstly, Slack and email use “threads” in conversations which do not provide a solid solution for information and communication organization. Secondly, until you have general “external” access to social networks, email will still be used for marketing and networking.

"LinkedIn, for example, has the potential to replace external email, but I don’t believe LinkedIn users are actively using InMail to replace their email conversations,” she said. But at the end of the day, Forth believes people should always turn to the communication method that works best in any given situation.

“I think social networks can help kill off some email, but face-to-face, real-time collaboration will make the big difference. Give people a way to quickly, spontaneously and easily connect for quick real-life conversations instead of using email and chat to communicate.”