Early tech giant

AOL

This company was known for its iconic "You've Got Mail" notification and dominated dial-up internet in the 1990s.

AOL" fits as the answer because it was one of the first major internet companies, dominating the early days of online services in the 1990s and early 2000s. The clue "early tech giant" points to its once-massive influence, especially with dial-up internet, email, and instant messaging. While not a household name today, AOL was synonymous with getting online for millions of users back then.