Problems Indexing Thunderbird Emails with CDS ver 8.3.2

It appears that the Copernic / Thunderbird connection has improved. Received email that Tony Ruggiero  had posted a reply on this topic, so checked CDS to see how well it was (or wasn't) doing, and have only found one function that seems to glitch now:  Some of the email messages show up twice in CDS, once with Normal Preview, and once with "Cannot be previewed," whereas a week ago MOST messages showed up as "Cannot be previewed."  My best guess is that either T'bird has changed something, or perhaps it has taken this long for the CDS Index to catch up (did do a bunch of re-organization within T'bird as was having multiple issues with it).

Settings are shown below, and have NOT been changed since the initial instructions to add the T'bird Connector and ensure that "Legacy Plugin" is NOT activated.  

Also confirmed that CDS appears to be working fine with Outlook (Classic), at least for recently sent emails.  

Pleased to see the Copernic Help has been staying on top of this issue - hoping that it remains "Fixed!"

Having generated quite quite a bit of personal experience of this extension and the problems it can sometimes cause, allow me to add some tips:

• In CDS complains that the Thunderbird extension is not running check in the process manager for a process called "Copernic.Plugins.Mozilla.ThunderbirdExtensionApp" - this is normally started and stopped by Thunderbird when it is opened and closed. If it is not there and Thunderbird is running then you have a problem.
• CDS is noticeably slower when indexing Thunderbird mail with this new extension than it was with the legacy process (and older versions of Thunderbird) - I could index around 100,000 email elements a day with the old system but now manage only 25-30,000 elements/day. As I have a large mailstore with over 1 million elements a completely new index is taking over 4 weeks to create. According to Copernic support "....this is the drawback of using the Thunderbird APIs. They are not as quick at reading files and do not support parallel calls."
• The Thunderbird extension is known to crash - possibly falling over emails it doesn't like. It's easy to restart by stopping and starting Thunderbird
• Remember that Copernic normally starts with Windows. Thunderbird does not. If you want to avoid Copernic complaining on startup that the extension is missing, then set up Windows to autostart Thunderbird. I don't consider this good practice, but it's a workaround.
• If you have the "Indexing Status" enabled in CDS you may see long pauses when beginning to index a Thunderbird folder, which sometimes result in a timeout (by default after 1 hour). Per the suggestion of Copernic support I have doubled the value of ThunderbirdServiceTimeoutInMs in the config file (config.xml in fhe folder %localappdata%\Copernic\DesktopSearch\) to 7200000 (=2 hours), but it just waits longer and still times out. I have found that if there is no indexing activity for 10-15 minutes and a timeout is likely, then it's easier to simply stop Thunderbird (and therefore the extension) and simply restart it. Indexing then seems to start again and continue normally. Copernic support say the timeout is related to reviewing large folders, but the folders I am getting the timeout on are certainly not large.

Here is the full explanation showing how to use the new Thunderbird extension. This will only work for Thunderbird 121 and higher.

Things to note: After installation of Copernic 8.3.3, restart Thunderbird and you will see a new Copernic add-on (yellow icon). Please enable this extension in Thunderbird and you will now be able to use the new Thunderbird extension with all the improvements.

If this does not show, you can enable the extension under the hamburger button > Add-ons and themes. Click on the gear icon and select "Install an Add-on from a file..." then select the file "ThunderbirdConnector.xpi" from this folder: "C:\Program Files\Copernic\DesktopSearch\ThunderbirdConnector" (Refer to image below for instructions)

Also make sure the "Use Legacy Plugin" option is NOT checked in Extensions / Licenses in Copernic.

Thunderbird and the extension must always be open for this to work.

 For any further support, contact us at support@copernic.com and the response will be quicker than on this forum.

Thunderbird and the extension must always be open for this to work.

"Well, this is perfectly obtuse, isn't it? ....  TB has been making some significant changes to their engine of late, and a LOT of previously popular and valuable third-party addons are currently broken..."  

Have the Connector installed in T'bird, but it doesn't work very well (lack of Previews; missed messages; poor formatting).  Have been too swamped with Urgent Things To Do to bother following up, but as with RGG really MISS having Copernic as a reliable means to index & search T'bird email.  

Well, this is perfectly obtuse, isn't it?  I'm running the latest version of CDS - v8.3.3.  I am also running the latest version of Thunderbird ("TB") - v137.0.2.  CDS is AWARE that I am running and using Thunderbird ("TB"), because there is a permanent warning message, highlighted in yellow, across the top of the CDS Search interface, which tells me to install the "Thunderbird Connector for Copernic Desktop Search" in "Add-ons and Themes" in TB.  But try as I might, I could not FIND that connector.  Argh.  So, having to dig into Copernic's \Program Files\ directory to extract a file that will enable me to manually install the connector... well, nothing and no one anywhere told me to do this.  So, thanks to Helmut for posting the workaround.  But it is a workaround, and from other posts here, it's clear that CDS's support for TB is currently tenuous at best.

Now, having said that, I do understand that TB has been making some significant changes to their engine of late, and a LOT of previously popular and valuable third-party addons are currently broken in the latest TB version.  But, at the same time, I purchased CDS specifically b/c, in their Advanced package, they have a whole line item indicating their support for TB.

Further note:  I anticipate that TB will be increasing significantly in popularity as Google slowly withdraws its support for Microsoft Outlook.  Outlook has never been good, but, in my opinion, it's always been lightyears better than gmail.com, and I had, for many years, used Outlook to access my Gmail accounts.  But no longer.  I am a now officially an Outlook refugee who found Thunderbird.  It is in everyone's interest for Copernic to make their (unique) support for TB rock solid and simple.  PLEASE.

I got this answer from Copernic (it works):
Things to note: After installation of Copernic 8.3.3, restart Thunderbird and you will see a new Copernic add-on (yellow icon). Please enable this extension in Thunderbird and you will now be able to use the new Thunderbird extension with all the improvements.

If this does not show, you can enable the extension under the hamburger button > Add-ons and themes. Click on the gear icon and select "Install an Add-on from a file..." then select the file "ThunderbirdConnector.xpi" from this folder: "C:\Program Files\Copernic\DesktopSearch\ThunderbirdConnector"

Also make sure the "Use Legacy Plugin" option is NOT checked in Extensions / Licenses in Copernic.

Thunderbird and the extension must always be open for this to work.

(April 12, 2025)  Also received a couple of 'unofficial updates' of CDS. Am now running the newest version (to the best of my knowledge: 8.3.3), which appears to FIND emails in Thunderbird, but does NOT display the contents, instead showing "Loading Preview" message followed by "This document cannot be previewed."

CDS does appear to be working with "Classic" Outlook. It does not currently work with "New" Outlook - am hoping that might change as "New" Outlook is presumably allowing local email storage.  

And, yes, have seen the message that Thunderbird Must Be Running - although that has normally been the case as it has been my Default Email app for some years (since Eudora), but TBird itself has been flakey since early Jan '25. Alas, finding a Desirable Alternative has proved fruitless.  

Having contacted Copernic support, they  have provided me with a pre-release version of a future CDS which includes a Thunderbird add-on/connector. I'm currently reindexing all my mails (over a million indexable elements) which will take over a week but initial results look good. The only downside is that Thunderbird has to be running all the time for Copernic to access the connector.

I have also just noticed this problem. I presumed I may have a corrupt message that was tripping up Copernic but I have moved messages around and rebuilt Thunderbird mail storage, but the problem is repeated. Most, but not all my mails since October 2024 are shown as "N/A" in the "To" and "From" fields, and these fields themselves are not indexed.

Although I have only just spotted it, this is a serious problem as it's clear the search results for recent mails are no longer reliable.