Are you using "push" in general terms to highlight that emails are not being reguarly synchronised (15 min polling), or do you specifically have an issue with the push service which delivers emails immediatly upon arrival on the server. '''For general synchronisation issues,''' Have you checked the app is excluded from any Android battery optimisations and allowed it to run unrestricted in the background. # Long press Thunderbirds launcher icon. # Click battery usage. # Enable background usage. The location and name for these settings can vary by phone manufacturer and android version. '''Push Service''' Android requires the app's push service to run in the foreground and display a permanant notification. If you close the app using the recent app list, the push service is terminated and won't receive new emails. If you're using the push service with Android 13 or later, check you've granted the app "Alarm & reminders" permission. See the guide linked below. https://support.mozilla.org/en-US/kb/configure-push-email-thunderbird-android