1. <blockquote>my new email notification are not ringing on the app</blockquote> The following link might be helpful: https://support.mozilla.org/en-US/questions/1497851#answer-1718158 2. <blockquote>it seems to be syncing for a long time because i set to sync for all of my emails?</blockquote> 2.1. You can configure how many days of emails you want to sync by following steps: "Settings" > "Accounts" section > tap the email account you want to configure > "Fetching mail" > "Sync messages from" > choose the option you prefer. 2.2. You can configure which folders to sync by following steps: Click three horizontal bars on the top left corner > tap the account you want to configure > "Manage folders" > tap the folder you want to configure > turn on "Enable sync" to sync this folder, or turn off "Enable sync" to not sync this folder. 2.3. If you are using Gmail, it is recommended to not sync "All Mail" folder. The following link might be helpful: Thunderbird and Gmail https://support.mozilla.org/en-US/kb/thunderbird-and-gmail Although the above link talks about Thunderbird (desktop), I think the concept can be applied to Thunderbird for Android, too.