Using IMAP on Yahoo mail any added subscribed folders (added via the web interface at Yahoo that have mail filtered into them by Yahoo (set on the web). These folders are set to check for new messages in this folder, only update the message count on Thunderbird launch.

They sometimes display a message count yet clicking the folder shows zero messages. Closing and reopening Thunderbird will then display the messages in that folder. Yahoo Trash also behaves this way. Clicking a folder or double-clicking it does not update the folder contents.

This is W10 latest 1909 and all updates, and Thunderbird is the 32-bit version.

also a bit like bug 1595169

I'm seeing different behavior than the first bug. All of the filters are on the Yahoo side and the folders are all IMAP. These will show the message count (usually) but do not show the list of messages even though they are set to check for messages every check-time.

Restarting Thunderbird with the folder selected causes the messages to show up.

They are actually there if I check via the web interface.

(In reply to rskunath from comment #2)

I'm seeing different behavior than the first bug. All of the filters are on the Yahoo side and the folders are all IMAP. These will show the message count (usually) but do not show the list of messages even though they are set to check for messages every check-time.

Restarting Thunderbird with the folder selected causes the messages to show up.

They are actually there if I check via the web interface.

Same.

more yahoo nonsense

(In reply to rskunath from comment #0)

Using IMAP on Yahoo mail any added subscribed folders (added via the web interface at Yahoo that have mail filtered into them by Yahoo (set on the web) and these folders are set to check for new messages in this folder,

By default, tb only checks new mail for Inbox and up to 4 of the most recently visited folders. The 4 are actually not checked but rely on the imap server to inform tb there is new mail via the imap IDLE function. I'm not sure if yahoo supports IDLE so only Inbox is guaranteed to be checked.
But I assume you mean you have set some special folders using the right-click property to have them checked for new email like Inbox and I assume you are saying you see the unread count on these go up but when you click the folder you see no new messages appear in the list?

only update the message count on Thunderbird launch. They sometimes display a message count yet clicking the folder shows zero messages. Closing and reopening Thunderbird will then display the messages in that folder. Yahoo Trash also behaves this way. Clicking a folder or double-clicking it does not update the folder contents.

What you describe I don't think I have ever seen reported before. You say you see the unread count for the folder increase (folder and count are bold) and then you click the folder name but no messages appear? If you visit another folder and then come back to the unresponsive folder, do the messages appear?
Do new message to Inbox appear as expected?

If you can duplicate this it might be interesting to see what tb produces in an IMAP:5 log. Information on how to produce a log is here: https://wiki.mozilla.org/MailNews:Logging . You can attach it using the "Attach New File" button above. Please include exactly what you were doing while recording the log.

more yahoo nonsense

Yahoo servers have been know to not always conform to standards :)

gene smith - Yes correct. I have 7 added folders and these are all mirrored on the Yahoo web side. The logic to move the messages happens on the Yahoo web side, and these all work flawlessly on my iPhone using the built-in mail client. Never a missing message. I have all of them (on TB) set to check for new messages on startup and every 10 minutes. I will see a new message count for these folders in TB, a top few will have the messages inside but the rest won't, even though they indicate that there are new messages. I have to select one of these, close and reopen TB and then the messages appear. They won't appear if I click or double-click the empty folder with the new message count, or if I stay there and wait. The inbox is working normally.

Can you duplicate the problem with just one folder having new messages placed in it? You say the "top" folders will have message but the "rest" don't? I've tested it with one folder and don't see a problem. Using a separate app, I put 10 messages in yahoo folder X that are unread. Then in TB, I see the unread (bold) count for folder X go to 10. When I click and open the folder I see all 10 messages in the list as expected.

Then I created 7 folder in tb for yahoo, f1-f7 with the other app. With the other app I added to each of the folders 7 unread messages. Back on tb the 7 new folders all appeared and became bold and indicated each with 7 unread messages in f1-f7. Clicking on folders f1 to f7 sequentially, I see the 7 unread messages in the list for each folder.

What I am doing is equivalent, imap wise, to how messages are accessed in non-inbox folder when yahoo puts them there with its filters. I'm not seeing a problem. So if you can try to duplicate this using the minimal number of folders and messages and record the imap log like I requested in comment 5 then I might be able see what is not working for you. Thanks.

I created the batch file and ran TB twice. Each time some of the folders exhibited the described behavior of showing unread messages but none were visible in the folder. This was even after waiting with the folder selected for several minutes .I don't seem to be able to attach the file but here is a link to grab it:

https://www.dropbox.com/s/ujgbcmo13y4dokt/imap.zip?dl=0

Let me know if there is anything I can run off or do more to help, and thank you :)

Thanks for the file. It looks like you select several folders but I'm not sure of which folder name has the problem. I see folders

NRC-AM-L
Topband-L
HCDX-L
IRCA-L
MediumWave Circle-L
plus Inbox and Trash

selected at different points in the log. Assuming NRC-AM-L is a problem folder, how many unread messages did tb indicate and how many messages were visibly listed? Same information for other problem folder recorded in the log would help too.

Also, I assume that if you select folder NRC-AM-L and all the messages are not visible, then you select something else, e.g., Topband-L, and then go back to NRC-AM-L that you still don't see all the expected messages? Only tb restart shows them?

I see there are 12 new messages appearing in NRC-AM-L. The 12 headers are all fetched so tb probably knows there are 12 unseen messages and displays this in the folder list in bold. Tb then fetches only 3 of the new messages. These come in OK. Then tb tries fetching some of the others and some seem to succeed and others don't. I see quite a lot of re-logins occurring to yahoo which shouldn't be necessary. Also tb sends logout. This indicates possible problems with tb/yahoo maintaining a connection.
Without detailed network monitoring (e.g., wireshark) it's sometimes hard to know who is "dropping" the connection. However in another bug we found that yahoo doesn't like the 5 connections that tb makes and drops the connection. This will occur when you are moving from folder to folder. (Tb makes a server connection for Inbox and for 4 of the most recently visited folders.) So you might try reducing the number of "cached" connections as was helpful for this other yahoo related bug: bug 1595169.
Go to server settings for the yahoo account and click the "advanced" button. In there you can reduce the default number of connection from 5 down to 3 or less. After making this change, I recommend restarting tb so all fresh connection to yahoo are established. If this doesn't help, just set it back to the default value of 5, but tb should work OK with fewer connection if yahoo is not allowing 5.
Please try this and I'll keep looking at the log and see if anything more jumps out.

I reduced the connections to 3 and that seems to have settled it down. I do have 2 Yahoo accounts setup in TB, one is stock, no added anything and the other has the filtered folders of hobby-type email lists. I'm not sure if having 2 accounts setup was a part of the connections issue or not?

But it's working better now, thanks..

Let's call this a duplicate of bug 1595169.

(In reply to Wayne Mery (:wsmwk) from comment #12)

Let's call this a duplicate of bug 1595169.

*** This bug has been marked as a duplicate of bug 1595169 ***

You made this a duplicate to an INVALID BUG.

(In reply to Worcester12345 from comment #13)

(In reply to Wayne Mery (:wsmwk) from comment #12)

Let's call this a duplicate of bug 1595169.

*** This bug has been marked as a duplicate of bug 1595169 ***

You made this a duplicate to an INVALID BUG.

I do not think that was in error