Twitter accidentally sent emails asking users to confirm their Twitter accounts Thursday night. The emails began around 10 PM EST, with numerous Twitter accounts operated by BleepingComputer and its writers receiving the emails. Even though the links in the emails all looked legitimate, we immediately became suspicious that it was a phishing attack. It turns out that the confirmation emails were not a phish attack but simply an accident by Twitter. For those who wake up and find the Twitter confirmation email sitting in their inbox, you can safely ignore the message and simply delete it.
Source: https://www.bleepingcomputer.com/news/security/twitter-accidentally-sends-suspicious-emails-asking-to-confirm-accounts/