NGT48 Mail is an official mail application for fans of NGT48 members. By subscribing to your favorite member, you can receive exclusive emails that can only be read within this app. The app also allows you to reply to the emails sent by the members. The replies can only be seen by the members and not by other users. Additionally, the app sends birthday emails to subscribers on their registered birthdate. The app is free to download, but the email feature is a paid service that costs 400 yen per member per month. The service is automatically renewed every month after the initial paid registration. Users can cancel the service by turning off the auto-renewal 24 hours before the contract period ends.

The NGT48 Mail app is available on Android and developed by ENTERMEDIA INC. The app is categorized under the lifestyle section of the Google Play store. For payment, users will be charged through their Google account. The app's terms and conditions and privacy policy can be found on the NGT48 official mobile site.