Puzzling. This appears to be your first attempt to get help, yet your wording implies frustration at being ignored. Please show patience and courtesy and a volunteer will attempt to assist you. What is your problem? Please include any details that may be helpful. For example, did this happen with an upgrade? Are you a new user? Is your account POP or IMAP? Is there a specific error message you are receiving? If you are having troubles in accessing the account, including screenshots of input and smtp server settings may help. Thank you.

THIS is not my first attempt at getting help.

And I would thank you to not engage in condescending remarks such as yours is.

While no longer being an IT professional I was a decade ago, I am since retired and not active in diagnosing and solving problems so I am not cognizent of the internals of Thunderbird.

I am certainly not a new user, having used Thunderbird since the 90s on both M$ and Apple products.

When thunderbird started on login this morning, aside from the marketing blurb on how wonderful the latest version is, I had a broken system - all talktalk folders gone, all filters gone, only the Apple .me mail account active with all of its folders. And continual, on receipt of new mail warnings about missing filters. Some semblance of reality was only restored after entering debug mode.

And, after searching through the help files and a look in the community, what do I see? Similar problems to mine (in the past - 2021) with no replies.

Frustrated? I confess that I am.

No apologies here. We are volunteers. Your venting here does not serve you well. Yes, some problems may be similar to yours, but we have many thousands of contented users.

I wasn't expecting an apology - if you pay attention to what I wrote you will comprehend.

I was expecting a description of how to fix it and that is something I, so far, haven't perceived from anyone.

Still, I'm not about to engage in handbags at dawn.

Thanks for your lack of input.

I just had to read what a 1000+ words to get even a vague idea what the issue is.

I will summarize.

all talktalk folders gone, all filters gone, only the Apple .me mail account active with all of its folders. And continual, on receipt of new mail warnings about missing filters. Some semblance of reality was only restored after entering debug mode.

What I have established is that you appear to be using an apple product. Something around 5% of Thunderbird users have. None of those who volunteer in support use Apple routinely as far as I know. Given the UNIX basis of the operating system, often issues are related to permissions. But I can not venture even a guess if that is the case here as there is no real information to work with. only venting and assertions that your first question on the forum is not your first attempt to get help.

The forum does have a lot of folk who do not get answers. Sometime I look at the topic and just can't be bothered leading someone out of their ignorance or looking up the appropriate support article and force feeding it to them. Other times I actually have to go out and earn a living. As no one gets paid to be here, I assume this is similar to all the regular volunteers. But going over the failures of users and forums is not going to more forward with your apparent issue.

So now we are at the point of asking is the issue still continuing? Many issues has a way of resolving themselves, especially if the issue is an upstream outage. Or an overzealous antivirus/security program.

I am assuming your account with talktalk is an IMAP one. This is based on the fact that when there are connectivity issues with an imap account then folders routinely do not get found and are in fact often deleted locally as no longer existing.

So when you select get mail. What is the error message you get about talktalk? not the thousand and one side issues about filters. What is the connectivity issue with talktalk? Which you do not mention existing. So perhaps that is not where the issue lies.

If nothing appears as an error related to talktalk connectivity, open the error console. (Ctrl+Shift+J) Clear it using the trash icon and attempt to get mail again. What error show there? (note there is a right click copy message and an all messages menu entry to make sharing a little easier.)

Either the mail provider's imap server is not presenting that folder to Thunderbird, or Thunderbird is flubbing it.

> I was expecting a description of how to fix it and that is something I, so far, haven't perceived from anyone.

This requires understanding both the cause and the solution. Clearly, we don't yet know either.

Well, thanks for all the advise that did not help.

The frustration eventually got the better of me and I decided to use my long expired unix system admin skills to try and determine the cause underlying the post upgrade behaviour of Thunderbird.

I found under the "Profiles" folder there is, three folders down, a folder named mail.talktalk.net and in this folder the file "msgFilterRules.dat" can be found.

Opening this file in a regex capable editor permitted some examination of these "rules" and this is what I found:

Each rule comprises a collection of statements with preceding labels such as: name="a name" enabled="yes" type="17" action="Move to folder" actionValue="mailbox://<myname>%40talktalk.net@mail.talktalk.net/<destination folder>" condition="a condition which determines if action if to be taken"

I am using the "<" and ">" brackets to indicate some variable value, such as <destination folder>.

The "actionValue" statement is the interesting one because not all the statements in the file have this form. In fact almost all of them had this form: actionValue="mailbox://<myname>@mail.talktalk.net/<destination folder>"

And it is the case that when Thunderbird tries to process a rule in this latter form it trips up and emits and error message like those posted previously.

And not only was there this format error but the Thunderbird upgrade had also inactivated a lot of the previously active rules.

To sum up, I copied the "msgFilterRules.dat" file and changed the "<myname>@mail.talktalk.net" values to "<myname>%40talktalk.net" and enabled the previously inactivated rules. This fixed the problem.

Is it a bug? Did the upgrade trip up in its processing of the "msgFilterRules.dat" during the upgrade?

I hope this helps if others have experienced similar problems.

PS I preserved the original "msgFilterRules.dat" file before making changes and overwriting the file in its original location. Also, these changes were made while Thunderbird was shut down.

I am trying to determine whether existing bug reports cover this, or a new one needs to be filed. In my on filters, I never see "@" in actionvalue - and I have hundreds of filters.

Reporter, please help clarify two points:

1. You had previously written you got "warnings about missing folders" - but eventually you determined none were missing?

2. Do you know whether filters previously worked with "@" in the filter? In other words, do we know if an update changed the actionvalue, or rather that the actionvalue has not changed but the filter stopped working with that actionvalue containing "@"?

Sorry, I'll try to clarify.

I have two mailboxes set up; talktalk.net e-mail - the path to the rules file is: Profiles/lndo0dg1.default/Mail/mail.talktalk.net/msgFilterRules.dat

and me.com e-mail - the path to the rules file is: Profiles/lndo0dg1.default/ImapMail/imap.mail.me.com/msgFilterRules.dat

It was totally the case that the ALL the filters were broken on the talktalk e-mail account, except for one which I had probably setup after the upgrade - that is how I noticed the difference in behaviour, it's actionValue format was not the same as the others. It had the "%40talktalk.net" before the @ sign in the actionValue statement.

Because the talktalk account has the most e-mail it was what grabbed my attention and I wasn't getting and messages from the me.com account. But after the initial panic had subsided it seemed that the me.com account was behaving normally and was filtering successfully - I don't get many e-mails via that route anyway so it wasn't a priority

The majority of the had actionValue formats similar to what I have listed below and they produced the errors I complained about: name="From contains: @wikileaks.shop" enabled="yes" type="17" action="Move to folder" actionValue="mailbox://derrick.steed@mail.talktalk.net/Mailing%20Lists" condition="AND (from,contains,@wikileaks.shop)"

The few rules in the talktalk rules file that worked had actionValue formats similar to what I have listed below: name="From contains: @wikileaks.shop" enabled="yes" type="17" action="Move to folder" actionValue="mailbox://derrick.steed%40talktalk.net@mail.talktalk.net/Mailing%20Lists" condition="AND (from,contains,@wikileaks.shop)"

Out of curiousity I have now checked the me.com rules file (I have not made any changes to the msgFilterRules.dat file for the me.com account) - the path to it is: Profiles/lndo0dg1.default/ImapMail/imap.mail.me.com/msgFilterRules.dat

And it looks like this: name="From contains: @rumble.com" enabled="no" type="17" action="Move to folder" actionValue="imap://frustrated.genius%40me.com@imap.mail.me.com/Rumble" condition="AND (from,contains,@rumble.com)"

Let me know if this helps please.