Many people think social media has pushed email engagement out of style, but the data tells us a different story: email is still a powerful marketing tool for businesses to use, especially in targeting millennials.

It's been four decades since marketer Gary Thuerk, often referred to as the "Father of Spam," sent out the first email blast on record. The all-caps message, sent pre-Internet, invited 400 recipients to new product presentations that Thuerk's company was introducing at the time.

While Thuerk's note may be antiquated in an era saturated with emojis and clickbait, his marketing method is still in fashion. In fact, this 40-year old marketing tactic is not dead. It's not even "over the hill." A 2016 study by Adestra shows that 73 percent of millennials -- the generation with the most buying power on the planet -- prefer getting emails from businesses over any other communications channel.

Liviu Tanase, a serial entrepreneur and the founder of email verification system ZeroBounce, says using email to communicate with millennials can be a great tool for businesses to appeal to the Gen Y consumer.

"Email enables companies to speak to an audience with genuine and personal messages, which is especially important to millennial consumers with a strong desire to connect," says Tanase.

Here are some other ways you can use email marketing as a boon to your business:

1. Use direct to consumers inboxes.

A business can have tens of thousands of followers on Facebook or Twitter, but the line of communication on those platforms can be hard to find. Email, on the other hand, is a very direct way of getting your recipient's attention. It puts your reader in the driver's seat in a beneficial way in that it allows him or her to read messages on their schedule. The conversation won't disappear in a constantly updating feed or a slew of notifications, which makes it easier for recipients to respond (or forward) on a timeline that works for them.

Sure, messages can get lost in overwhelmed inboxes. However, landing your message makes for a stronger chance that someone will read a note sent directly to them when competing with a tweet disseminated to 20,000 ever-changing news feeds.

2. Take advantage of Millennial's purchasing power.

Young adults from both the Millennial generation, along with their Centennial counterparts (those born in the mid-1990s to mid-2000s) not only still see email as highly relevant, but according to Adestra, 46 percent -- nearly half of them -- find email important when considering purchases. That means there can be a significant return on investment when using this fairly cheap marketing technique. In fact, a 2016 report by Campaign Monitor found that every $1 spent on email marketing translates into a $44 return.

Tanase says this is a result of younger generations' desire to build connections with brands they use. But this is also a reason that it's also important for businesses to take steps to ensure deliverability of their messages. Tanase suggests using a double opt-in confirmation before sending to new recipients, which requires a user's confirmation that she has joined your correspondence list. "Emailing people who didn't confirm to receive emails from you or your brand will very possibly get your email marked as junk, and that will hurt your inbox rate."

Menachem Ani, founder and CEO of the digital marketing agency JXT Group, agrees.

"Email is based on trust and the idea that you'll send the consumer content that is relevant and engaging," says Ani. "Therefore, it's very important to respect the user's inbox and create a compelling email marketing strategy. When utilized properly, email marketing can drive significant ROI, especially as compared to other ad channels."

3. Vaporize vulnerabilities by prioritizing security.

David W. Schropfer, CEO of cybersecurity company AnchorID and host of DIY Cyber Guy Show, says that while email marketing is a great way to get your brand's message out, you still need to be careful about how you handle what comes back in.

Schropfer advises not to put a link to a direct email address to enhance customer service. "If you want to create a reply channel, include a link to a 'Contact-Us' page on your web site, and post a contact form with a Catcha (or similar product) to ensure you don't get overwhelmed by bots.  

Continues Schropfer, "If you must include a reply email address in a marketing campaign, work with your network security team to train anyone who screens or reads these reply emails to avoid common mistakes. NEVER click a link in a reply email to a marketing campaign without checking with your network security team first."