User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Firefox/60.0 Steps to reproduce: Hello all, Environment: - Debian GNU/Linux 9 "Stretch" - Thunderbird 60.3.0 - Orca 3.30 (latest stable) Orca master (from git) Steps to reproduce are described here 0) Start the Orca screen reader 1) Open a big folder (here I'm testing with a folder with only 600 mails) 2) Remove a conversation Actual results: Visually on the screen, the mail conversation is delete quickly but Thunderbird seems to take 5 seconds to send events to the Orca screen reader and in consequence Orca announce the deletion of a mail after 5 seconds. Expected results: Thunderbird should send the events faster as it was on Thunderbird 52 The current situation is really critical for us because 5 seconds is really slow for a software to respond. For blind or visual-impaired user, the only interface they rely on is the screen reader. Other users encounter many lags with Thunderbird with Orca on GNU/Linux, see on the Orca mailling list those threads: - https://mail.gnome.org/archives/orca-list/2018-November/msg00148.html - https://mail.gnome.org/archives/orca-list/2018-November/msg00056.html The Orca developer has already checked the time to process event and Orca takes less than one second to process them, see below, so it's why we're thinking of an issue in Thunderbird himself https://mail.gnome.org/archives/orca-list/2018-November/msg00119.html We (Hypra) would be OK to help to debug this as both QA and development but we'll really appreciate help on the way to debug such performances issues. Best regards, Alex.