Bugzilla

Fyi I experienced sent copy fails issues in TB 144.0b4 (64-bit) with both IMAP Sent folder and Local Folders > Sent (safety net). It could be linked to network issue as I had a bit of latency (100-125ms) and some intermittent packet loss 3-10% that was causing communication delay when issue started to occur.
Basically I sent email, that were delivered fine immediately and I first though copy to Sent folder succeeded as the sent email disappeared on screen. I did so with couple more emails, till I realised I could not find them in Sent in my IMAP account or TB Local Folders. Indeed, there were no longer appearing as an open window in the task bar TB icon... but if I minimised all the opened Windows from TB and other app, the message would appear as still trying to copy email to Sent folder on the IMAP server.
Cancelling this action would then prompt for saving email which if you click Save would store the email in Local Folders > Sent in TB on local computer. But that only worked for a couple of the emails... at some point other email just disappear from the screen without being saved. After which I found them again somewhere behind other windows, in the background, the prompt to save email even further behind! When clicking Save for each of the remaining emails that failed to copy, I was then prompted with a windows, after a while, saying: Copy fails... so they could not even be copied locally on the computer... with only the option to click Cancel.
If I click Cancel I would then return to the compose window of the email, as if it was not sent yet (but it was already with no copy saved locally or in IMAP). I could then re-send them and they would be saved correctly in the IMAP folder.
Obviously there is still something wrong with the way Thunderbird handle network related faults when sending emails and storing them to IMAP Sent folder.

Fyi I experienced sent copy fails issues in TB 144.0b4 (64-bit) with both IMAP Sent folder and Local Folders > Sent (safety net). It could be linked to network issue as I had a bit of latency (100-125ms) and some intermittent packet loss 3-10% that was causing communication delay when issue started to occur.
Basically I sent email, that were delivered fine immediately and I first though copy to Sent folder succeeded as the sent email disappeared on screen. I did so with couple more emails, till I realised I could not find them in Sent in my IMAP account or TB Local Folders. Indeed, there were no longer appearing as an open window in the task bar TB icon... but if I minimised all the opened Windows from TB and other app, the message would appear as still trying to copy email to Sent folder on the IMAP server.
Cancelling this action would then prompt for saving email which if you click Save would store the email in Local Folders > Sent in TB on local computer. But that only worked for a couple of the emails... at some point other email just disappear from the screen without being saved. After which I found them again somewhere behind other windows, in the background, the prompt to save email even further behind! When clicking Save for each of the remaining emails that failed to copy, I was then prompted with a windows, after a while, saying: Copy fails... so they could not even be copied locally on the computer... with only the option to click Cancel.
If I click Cancel I would then return to the compose window of the email, as if it was not sent yet (but it was already with no copy saved locally or in IMAP). I could then re-send them and they would be saved correctly in the IMAP folder.
Obviously there is still something wrong with the way Thunderbird handle network related faults when sending emails and storing them to IMAP Sent folder.

Most recent console errors:
````
13:50:38.728 NotFoundError: Could not open `C:\Users\richard\AppData\Local\Temp\nsemail-2.eml': file does not exist (NS_ERROR_FILE_NOT_FOUND)
13:50:42.327 NotFoundError: Could not open `C:\Users\richard\AppData\Local\Temp\nsemail-3.eml': file does not exist (NS_ERROR_FILE_NOT_FOUND)
13:50:46.720 NotFoundError: Could not open `C:\Users\richard\AppData\Local\Temp\nsemail-1.eml': file does not exist (NS_ERROR_FILE_NOT_FOUND)
13:50:51.037 NotFoundError: Could not open `C:\Users\richard\AppData\Local\Temp\nsemail.eml': file does not exist (NS_ERROR_FILE_NOT_FOUND)
14:02:02.160
mail.activity: onDownloadCompleted: TypeError: can't access property "activity", this._syncInfoPerFolder.get(...) is undefined autosync.sys.mjs:386:16
    onDownloadCompleted resource:///modules/activity/autosync.sys.mjs:386
    openWindowPrompt resource:///actors/PromptParent.sys.mjs:75
    receiveMessage resource:///actors/PromptParent.sys.mjs:18
    openPrompt resource://gre/modules/Prompter.sys.mjs:1224
    openPromptSync resource://gre/modules/Prompter.sys.mjs:1067
    confirmEx resource://gre/modules/Prompter.sys.mjs:1518
    confirmEx resource://gre/modules/Prompter.sys.mjs:299
    confirmDownloadMessagesForOfflineUse chrome://messenger/content/mail-offline.js:187
    toggleOfflineStatus chrome://messenger/content/mail-offline.js:62
    oncommand chrome://messenger/content/messenger.xhtml:1
14:02:02.163
TypeError: can't access property "activity", this._syncInfoPerFolder.get(...) is undefined
autosync.sys.mjs:377:49
    onDownloadCompleted resource:///modules/activity/autosync.sys.mjs:377
    openWindowPrompt resource:///actors/PromptParent.sys.mjs:75
    receiveMessage resource:///actors/PromptParent.sys.mjs:18
    openPrompt resource://gre/modules/Prompter.sys.mjs:1224
    openPromptSync resource://gre/modules/Prompter.sys.mjs:1067
    confirmEx resource://gre/modules/Prompter.sys.mjs:1518
    confirmEx resource://gre/modules/Prompter.sys.mjs:299
    confirmDownloadMessagesForOfflineUse chrome://messenger/content/mail-offline.js:187
    toggleOfflineStatus chrome://messenger/content/mail-offline.js:62
    oncommand chrome://messenger/content/messenger.xhtml:1
14:05:34.327
TypeError: can't access property "ownerGlobal", navigatedWindow.windowRoot is null
2 FormHandlerChild.sys.mjs:413:31
    notifyProcessRootOfNavigation resource://gre/actors/FormHandlerChild.sys.mjs:413
    onLocationChange resource://gre/actors/FormHandlerChild.sys.mjs:361
    #pushOrReplaceState resource://pdf.js/web/viewer.mjs:5667
    #tryPushCurrentPosition resource://pdf.js/web/viewer.mjs:5686
    #pageHide resource://pdf.js/web/viewer.mjs:5839
    closeTab chrome://messenger/content/tabmail.js:1128
    removeTabByNode chrome://messenger/content/tabmail.js:1146
    connectedCallback chrome://messenger/content/tabmail-tab.js:99
````