on Thunderbird for Android the push connection and the new mail alerts are separate settings, which catches a lot of people. check Manage folders > Inbox and make sure both Enable Push and Notifications are on, then Settings > your account > Notifications > New mail notifications. if it still only turns up when you open the app, set its battery usage to Unrestricted, and on Android 13+ allow “Alarms & reminders” for it (that’s in the app’s system settings, not under permissions). FairEmail is worth a try too if you get fed up with it.
on Thunderbird for Android the push connection and the new mail alerts are separate settings, which catches a lot of people. check Manage folders > Inbox and make sure both Enable Push and Notifications are on, then Settings > your account > Notifications > New mail notifications. if it still only turns up when you open the app, set its battery usage to Unrestricted, and on Android 13+ allow “Alarms & reminders” for it (that’s in the app’s system settings, not under permissions). FairEmail is worth a try too if you get fed up with it.