Junk filter sends most emails to junk - not learning

[marlonf]

I've been using Thunderbird since about 1995. About five months ago I switched all my accounts from POP3 to IMAP accounts in order to better manage my email between multiple devices. Since then, I'm struggling to get the Junk Filter to work well.

I have "enable adaptive junk controls" and "move new junk messages to the junk folder" selected. What happens is that about 75% of all my emails get sorted to the Junk Folder. When I go there and remove the junk flag some move back to the inbox automatically and some do not. I manually move the non-junk emails back to the inbox.

When I receive another email from that same person, it will get filtered to the junk folder again. This happens across a huge number of repeat non-junk emails. And yes, there is spam that does not get sorted to the junk folder as well.

I searched the web and this forum, but couldn't find anyone with this same problem. Perhaps if Thunderbird's junk filter is working for you, can you share your settings?

Thanks!

[LIMPET235]

Moving to Thunderbird Support...

[makaiguy]

• There are TWO places you need to have things set for junk mail.
  
  Overall Settings, menu path:
  [If running on Windows]: Tools | Options, or
  [If running on OSX]: Thunderbird | Preferences, or
  [If running on Linux]: Edit | Preferences
  .. then Security | Junk
  
  .. and ..
  
  Account-by-account Settings, menu path:
  [If running on Windows or OSX]: Tools | Account Settings, or
  [If running on Linux]: Edit | Account Settings
  .. then, under *each account* in the left pane, Junk Settings.
  
  Your IMAP account is a different account than your old POP account, so be sure things are set correctly in the new account as well as the old (sounds like you've done this, but just to be sure...).
• Much junk comes in with spoofed (i.e. fake) sender addresses, so the junk filtering is more influenced by message content and headers than by the name/address of the sender (if the sender is considered at all -- ??).
  
  To exempt messages from a particular sender from the junk controls, make sure that email address is in your address book, then in the settings the receiving account, under "Junk settings", in the "Do not automatically mark mail as junk if the sender is in" area, check the appropriate box (most likely Personal Address Book). Note that this is an account-specific setting, so if you have multiple accounts defined, be sure you do it in the correct account (or just do it in ALL accounts).
• Things classified as junk, when you click the "Not junk" button SHOULD go back to the Inbox from which it was moved when first classified as junk.
  
  (I haven't looked into this in detail in quite a long time, so take this with a grain of salt ...) I THINK it does this by adding an additional header to the message that tells it where the message came from, when the system classifies the message as junk. A ramification of this is if the message was placed into the junk folder by some other means (manual move or filter action) it may not have that header and so can't be moved back. If moved there by a filter, make sure the filter first does a [Set Junk Status To][Junk] operation before it does the [Move Message To][Destination folder] operation.
• If the junk filtering just isn't doing a good job, sometimes you need to just clean out the old junk database and let it start anew. You can do this by clicking the "Reset Training Data" button under your Global junk settings. As you further train it by marking things "Junk" and "Not Junk" its accuracy should improve.

[marlonf]

Thank you for your efforts to help. I "Reset training data" to start again. Thunderbird sends emails that I send myself to Junk, even though I have indicated "not junk" several times. I can make up a general email address and add recipients. That's a good idea.

Thanks again. Hopefully it will learn.