David, thanks for reporting your results. Can you retest please and tell us if this reproduces with a curent beta?
If it reproduces, please run the performance profiler: 1. You must be using Thunderbird 68 or newer - betas from https://www.thunderbird.net/en-US/channel/ or current nightly build from https://archive.mozilla.org/pub/thunderbird/nightly/latest-comm-central/ 2. Install profiler add-on into thunderbird 68 (or newer https://www.thunderbird.net/en-US/channel/ ) - get the add-on file from https://github.com/firefox-devtools/Gecko-Profiler-Addon/blob/master/gecko_profiler.xpi?raw=true and in Tools > add-ons click the gear to install add-on from file 3. Follow instructions at https://profiler.firefox.com/ (videos BASED ON FIREFOX at https://profiler.firefox.com/docs/#/./videos-intro ) 4. Create a profiler URL and post it here. -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to thunderbird in Ubuntu. https://bugs.launchpad.net/bugs/1012858 Title: "Sending of message failed" dialog needs 100% of one CPU as long as it is open. Status in Mozilla Thunderbird: Confirmed Status in thunderbird package in Ubuntu: Triaged Bug description: Priority: Low How to reproduce: - Attach a large file to a message to make the sending process need enough time for the third step. - press the "send" button - Interrupt the internet connection before the sending of the message can be completed Problem: The Dialog that pops up now telling the message could not be sent creates 100% CPU load for one CPU. What was to be expected: The dialog pops up and does not need any CPU power until a button is clicked. ProblemType: Bug DistroRelease: Ubuntu 12.10 Package: thunderbird 14.0~b1+build2-0ubuntu1 ProcVersionSignature: Ubuntu 3.4.0-5.11-generic 3.4.0 Uname: Linux 3.4.0-5-generic x86_64 ApportVersion: 2.2.2-0ubuntu2 Architecture: amd64 Date: Wed Jun 13 22:49:39 2012 EcryptfsInUse: Yes ExecutablePath: /usr/lib/thunderbird/thunderbird-bin LocalLibraries: /home/gunter/.thunderbird/fskw3xe2.default/extensions/mintr...@tn123.ath.cx/lib/tray_x86_64-gcc3.so SourcePackage: thunderbird UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/thunderbird/+bug/1012858/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp