This article originally appeared on ZDNet.

As Google Inbox approaches its fourth birthday, the Gmail-viewing alternative is set to be killed off in March 2019.

“Four years after launching Inbox in 2014, we’ve learned a lot about how to make email better-and we’ve taken popular Inbox experiences and added them into Gmail to help more than a billion people get more done with their emails everyday,” Google product manager Matthew Izatt said in a blog post.

“As we look to the future, we want to take a more focused approach that will help us bring the best email experience to everyone. As a result, we’re planning to focus solely on Gmail and say goodbye to Inbox by Gmail at the end of March 2019.”

SEE: Electronic communication policy (Tech Pro Research)

Inbox is available as a mobile app and as a web interface alternative to viewing Gmail accounts.

Across the lifetime of Inbox, some of its features — such as smart compose, nudges, and email snoozing — have found their way back into Gmail.

Inbox users moving back to Gmail that recoiled from its latest redesign are fresh out of luck if they want to continue to enjoy features that they have come to rely on, as many are not availble in classic Gmail.

Gmail users that are not using the latest design will find the option to opt-out removed next month.

As someone that recently returned from vacation, the ability of Inbox to automatically create trip bundles was invaluable, and appears to have no analogue in Gmail.

On the hardware front, Google is expected to launch the Pixel 3 and Pixel 3 XL on October 9 in New York.