Migrate your data to Proton [https://proton.me] and stop using Outlook is one option.
Calendar - Proton Calendar app
Email - Proton Mail app
Contacts - my solution is split:
(a) All contact details including high value contact information (eg: DOB, address, email) are stored in the contacts section of the Proton Mail app. The contacts are in the cloud so no synching required.
(b) Basic contact information (eg: name, phone number) is in the AOSP stock contacts app. Not synched. Export and back up the csv file periodically to PC.
All PC based activity is via a web browser logged into Proton for contacts, email and calendar. Contacts within Proton Mail contacts will become available within the Proton Mail app, cloud calendar will sync with the Proton Calendar app.
High value contact information is enclosed in the Proton Mail app and not subject to Android contact permissions.
The calendar information is enclosed in the Proton Calendar app and not subject to Android calendar permissions.
Proton Calendar
https://protonmail.com/download/CalendarAndroid/ProtonCalendar-Android.apk
SHA256 fingerprint of the signing certificate
DCC9439EC1A6C6A8D0203F3423EE42BCC8B970628E53CB73A0393F398DD5B853
Protonmail Email
https://protonmail.com/download/MailAndroid/ProtonMail-Android.apk
SHA256 fingerprint of the signing certificate
DCC9439EC1A6C6A8D0203F3423EE42BCC8B970628E53CB73A0393F398DD5B853
Reference: https://www.protonapps.com/protonmail-android
If your GrapheneOS device is lost or stolen the sessions for both the Proton Calendar app and the Proton Mail app can be revoked using your PC.
https://proton.me/support/log-out-all-other-sessions