It is a sad day for internet users. The man who has been credited with inventing email, Raymond Tomlinson, passed away of a suspected heart attack over the weekend.

Back in 1971, Tomlinson invented email on ARPANET (an ancestor of the internet). As with most things, his version of email didn’t take off right away. In 1977, it finally became a standard and changed the way that we communicate forever.

With that invention of email, he also made the user@host format popular. It is still used with email today, as well as in other forms of digital communication. The use of the @ symbol in email also laid the groundwork for modern social media, like Instagram and Twitter, that use that symbol for private messages to other users on the platforms.

Many have been posting their thanks to Tomlinson on social media. Google’s Gmail tweeted “Thank you, Ray Tomlinson, for inventing email and putting the @ sign on the map. ” earlier today as well.

So, thank you, Mr. Tomlinson, for your invention that changed the way we communicate forever. Rest in peace.