Important part of collaborative translation process is the ability to notify project members about new tasks. There are several ways to do this, starting with simple Slack integration (see project settings), however the most popular method is sending a notification e-mail. In order to do that, once a developer adds new keys, it is necessary to select those in the editor and select "E-mail to contributors..." from the blue popup action box.
You will be able to select individuals or add them in groups by language teams. There is an option to type individual e-mail message, while Lokalise will automatically add a link to selected keys to this e-mail.
When creating a notification, give it a name, so you or any other users can Filter by this notification and see what was included.