For Gmail, you would have to configure the account. The APK can be installed on Android, for users with 5.0 or higher. You can specify certain times during which you do not want to receive emails thanks to the Silent Time function. K-9 Mail has support for gestures and offers options to manage notifications. Furthermore, privacy has also been improved with a new encrypted message support which provides an additional layer of security. The design is simple as you will be able to navigate easily in the application. This new version comes with a new interface which is more comfortable and intuitive for Android users. The new version is v5.717, which can now be downloaded from GitHub. It is compatible with Gmail, Outlook or Yahoo, for example. It has the advantage of allowing to add several email accounts from different platforms so that you will be able to access all from a single application. K-9 Mail is an application that has stood out for providing users many customization and configuration options. It is considered as one of the most interesting Android applications for open source enthusiasts. This application has just undergone a radical change. K9 Mail is an email application that is available as an APK for Android. If you are looking for a customizable email application in which you can manage multiple accounts, K9 Mail is an ideal open source alternative. K-9 Mail now requires Android 5.Gmail is the most popular email application on Android, although there are many other options that are of great interest to users.Deprecated support for the WebDAV protocol new accounts can no longer be added.Changed periodic background sync and push implementations to work much more reliably.Here's the full changelog for the K-9 Mail v5.8

However, the developer says this won't affect existing WebDAV accounts, and they will continue to work for now.

It's also ending support for WebDAV accounts. The new version now requires Android 5.0 and above. The K-9 Mail v5.8 is rolling out on the Google Play Store, and it brings some much-needed improvements to this OG email client, including a redesigned interface, improved background sync, better image previews for image attachments, improvements to Unified Inbox and end-to-end encryption, and various bug fixes.

K9 mail android