Alternatives to Gmail
Sebastiano LicciardelloWorks on MicroG?
No..
Open Source Services
Ctemplar
CTemplar provides a safe and secure platform for sending emails and sharing files by using 4096-bit end-to-end encryption. More details
Tutanota
Tutanota enables you to use the benefits of the cloud - availability, flexibility, automatic back-up - without compromising on security. With Tutanota's built-in encryption you own your data, no one else can access it. Tutanota comes with a light & beautiful GUI, dark theme included, with instant push notifications, auto-sync, full-text search, swipe gestures and more. The open source email app Tutanota enables you to send end-to-end encrypted emails to anybody. Even emails that are being sent without end-to-end encryption and all your contacts are stored securely encrypted on the Tutanota servers.
ProtonMail
ProtonMail is the world’s largest encrypted email service with millions of users. The ProtonMail secure email app for Android brings easy-to-use email encryption to your mobile device by seamlessly integrating PGP end-to-end encryption. ProtonMail also provides a modern user interface with a full set of innovative features such as customizable swipe gestures and the ability to send expiring emails.
Closed Source Services
Outlook
⚠ Privacy Alert: It sent big data to Microsoft Server
Yandex Mail
⚠ Privacy Alert: It sent big data to Yandex Server
Open Source Client
FairEmail
FairEmail is easy to setup and works with virtually all email providers, including Gmail, Outlook and Yahoo. This app is deliberately minimalistic by design, so you can concentrate on reading and writing messages.
K9 mail
E-mail client supporting multiple accounts, POP3, IMAP and Push IMAP.
Closed Source Client
⚠ Privacy Alert: Maybe sent some data to their servers..
AquaMail
Aqua Mail doesn't store your passwords on alternative servers. You can use OAUTH2 to login in Gmail, Yahoo, Hotmail and Yandex without entering a password for even higher level of security. Presents numerous settings and customizations. Tracker removed mod (require restore backup from normal version to work)
Spark
E-mail app with all the great features: swipes (long/short), snooze, add (multiple) attachments from the cloud, support for various e-mail services and more.