read received deleted email notifications

You're posting to the Firefox for Android support forum. Firefox is a browser and doesn't handle your emails. In case you're using Thunderbird as an email client and have a question about it please say so, then we can move your question into the Thunderbird queue. If you're accessing your emails through webmail, please contact your email provider. https://support.mozilla.org/en-US/kb/problems-with-email-how-to-find-help