You can turn off junk mail controls as far as Thunderbird is concerned. It's debatable whether this is a good idea or not. http://kb.mozillazine.org/Junk_Mail_Controls

However, spam filtering also happens on the server, before Thunderbird can process incoming messages. So I don't think you have a choice, you'll have to check your junk folder on a regular basis. Depending on your account type (POP or IMAP) you may even have to login to your account via webmail to do that.

Thank you for your reply. Very helpful. I have also read the article in the link you provided, although much of it was beyond me. If I understand correctly then the folder Thunderbird calls “bulk” contains emails the provider’s server has classified as spam/junk and the folder Thunderbird calls “junk” contains emails that Thunderbird itself has classed as spam/junk. Neither can be considered good at what they do as both of them filter out some messages from any given source whilst letting other messages from the same sources pass through to the inbox. Your conclusion that I will have to check my junk folder on a regular basis is obviously correct but it does mean that the junk filters can’t be trusted so why not pass all messages direct to the inbox for me to assess. It is clear now that isn’t possible. Thank you again.

If I understand correctly then the folder Thunderbird calls “bulk” contains emails the provider’s server has classified as spam/junk

"Bulk" is typically used by Yahoo/AOL/Verizon accounts.

and the folder Thunderbird calls “junk” contains emails that Thunderbird itself has classed as spam/junk.

"Junk" is used by Thunderbird by default for all account. However, if the provider's server uses "Bulk", you can tell Thunderbird to use "Bulk" as well for this account in Account Settings - Junk Settings. When doing this, the original Thunderbird "Junk" Folder for the account can be deleted.

Neither can be considered good at what they do as both of them filter out some messages from any given source whilst letting other messages from the same sources pass through to the inbox.

As explained in the article, the Thunderbird built-in junk filter does not use static rules. It needs to be trained what's Junk, and also what's not. Did you do that?

If you want to delete messages from a particular sender with a fix email address, you can create a filter. http://kb.mozillazine.org/Filters_(Thunderbird)

it does mean that the junk filters can’t be trusted

I'd say can't be trusted 100%. With the proper training the Thunderbird junk filter becomes pretty reliable over time. This isn't new though, it's always been like this.

so why not pass all messages direct to the inbox for me to assess.

You didn't tell about your account type. With IMAP, you can designate "Bulk" as junk folder to be used by Thunderbird. Since I doubt you can disable junk filtering on the server, you'll still have to check. With POP, you'd still have to check "Bulk" on the server via web browser.

Thank you again. My account is yahoo and I believe it is IMAP. I did try training it some time ago but gave up after a while as I thought Thunderbird was having learning difficulties but the artice you linked tells me it needs to be told hundreds of times and also needs to be told about junk and non-junk. I obviously didn't do it right or persevere long enough. Given that yahoo is generating the bulk file and that probably can't be prevented I think I'm just going to have to remember to check bulk and junk regularly as well as inbox. Not a big problem, just a minor irritation. But thank you for your time and patience.

Things to be aware of. Yahoo offer no way to opt out of their junk filtering. SO mail going to bilk is done by yahoo and they refuse to allow their users to determine what they think is not junk. I do think that will not mark mail as spam is the from address is in your yahoo online address book.

To exacerbate the issue a little Thunderbird does not default to checking the bulk mail folder for new mail on most installations. Right click the folder in Thunderbird, select properties and then in the General information tab make sure the folder is get messages when checking for new mail.

I would suggest you ensure that all folders are set to check when getting new mail and that you pay attention to the blue coloring on folders, even spam to make you aware there is something new and unread there to check.

Thank you. It might be obvious really but it hadn't occurred to me that Thunderbird's address list and Yahoo's are not the same. My bulk folder collects a large number of emails but only those from a very small number of senders are of importance to me. I've added their email addresses to the yahoo list so hopefully this will stop those from being junked. Thank you for your help

I have a similar concern with the "Bulk Mail" folder. I am using IMAP with AOL. I just noticed some messages from today in "Bulk Mail" in Thunderbird. I have junk mail filtering disabled in Thunderbird. I know AOL puts mail in a Spam' folder. But the Bulk Mail folder does not appear in my AOL account when I access it with their web interface, nor in the other devices I use to check my AOL mail (Mac, iPad, iPhone, all using IMAP). I only see the Bulk Mail folder on the Thunderbird interface, so I have would think it is strictly a Thunderbird feature. However, I have other IMAP accounts (work servers) that I access with Thunderbird, and they don't have a Bulk Mail folder so I don't know why it would treat AOL differently. Since I can't see it from any other device, I would like to disable the Bulk Mail classification as I have with Thunderbird's Junk Mail. If anyone knows how to disable it, I would be grateful!

RGEarley,

please start a new topic for your problem. https://support.mozilla.org/questions/new