I should say, it work sometimes, but not others.

Assuming you have used right click on email > Move to > select destination

Are you moving the email to another folder within the same mail account? After moving email - select folder you moved email into and then reselect the 'Unread' folder. Do you find the email no longer appears in 'Unread' if you select another folder as above, but remains in 'Unread' if you keep focus in 'Unread' ?

Is the 'Unread' folder a standard folder you created which receives auto filtered emails? OR do you always manually put unread emails into the 'Unread' folder? OR have you used 'Edit' > 'Find' > 'Search Messages' (via Menu Bar) or 'Tools' > 'Search Messages' (via the menu app icon) and created a search filter to locate 'Unread' mail and then saved results as a 'Search Folder'?

Thanks very much for your response, Toad-Hall. Here are your questions with my responses. Assuming you have used right click on email > Move to > select destination

I had been dragging and dropping, but this method has the same result.

Are you moving the email to another folder within the same mail account? YES (not shouting - easier to see) After moving email - select folder you moved email into and then reselect the 'Unread' folder. Do you find the email no longer appears in 'Unread' if you select another folder as above, but remains in 'Unread' if you keep focus in 'Unread' ?

It remains in UNREAD all the time, no matter which other folders I go to. I go from folder to folder all the time, but nothing affects these unread messages. Did you see I re-posted to say this is an intermittent problem. Looking at the recalcitrant emails, I have just realised the not-working ones I have there now are all from the same business (2 different people). They are business emails. I have had the problem before, from another business I'm pretty sure.

Is the 'Unread' folder a standard folder you created which receives auto filtered emails? I THINK I DID THIS ONE. When an email arrives, it goes into the INBOX and also shows up in the UNREAD folder under INBOX. When I move the email to it's destination folder (under INBOX), it disappears from INBOX but stays in the UNREAD folder if it's one of these nasty ones.

OR do you always manually put unread emails into the 'Unread' folder? NO OR have you used 'Edit' > 'Find' > 'Search Messages' (via Menu Bar) or 'Tools' > 'Search Messages' (via the menu app icon) and created a search filter to locate 'Unread' mail and then saved results as a 'Search Folder'? I don't think so.

Again, many thanks for posting.

re :Is the 'Unread' folder a standard folder you created which receives auto filtered emails? I THINK I DID THIS ONE. When an email arrives, it goes into the INBOX and also shows up in the UNREAD folder under INBOX.

That would imply you have set a Message Filter. But is it set up in Thunderbird or in the webmail account? Check Thunderbird.

• 'Tools' > 'Message Filters'
• In list select the filter you created specifically for putting emails into the 'Unread' folder.
• Then click on 'Edit' so you see the actual filter.
• Upload an an image of it.

Do you have more than one filter which puts email in Unread. If yes, post an image of that one as well.

The point is this....If you have a filter putting a copy of email into Unread then moving an email out of Inbox to another folder would have no effect on an email in 'Unread' folder.

re : 'Tools' > 'Search Messages' (via the menu app icon) and created a search filter to locate 'Unread' mail and then saved results as a 'Search Folder'? I don't think so.

To confirm folder type...

• Right click on the 'Unread' folder and select 'Properties'

What do you see ?

Does title say 'Edit Saved Search for Unread' and contain text saying 'Match all of the following' ? OR Does title say 'Folder Properties' and have tabs such as 'General Information and Retention Policy' ?

Are you using an Imap or Pop mail account ? Is it a gmail account ?

Hi Toad Hall. I very much appreciate the time you're spending on this. I can see that I haven't set up a Message Filter. There are no filters there to deal with UNREAD emails.

"Does title say 'Edit Saved Search for Unread' and contain text saying 'Match all of the following'" BINGO! That's the one. Exactly. And in the box it says: Status isn't Read

In Server Settings, it says: Server type: POP Mail Server.

It's not gmail. It's a private domain.

Info explains that you created a Search Folder to display any email with an unread status. That 'Search Folder' detects Unread mail in specific folders.

When email is in 'Inbox' you want it to be detected and display in the 'Unread' folder. You say "I don't want to mark the email as 'read', because then it won't show as 'unread' in the subfolder, which I want it to do," But when you move an 'unread' email out of 'Inbox' to a specifc folder of choice, you do not want that email to be picked up as 'unread'. You say the problem emails are specific business emails (which remain in Unread ) - do you move them to a specific folder just for those business emails? Is that specific folder somehow set up to be included in the search parameters?

• Right click on 'Unread' search folder and select 'Properties'.

It seems you only want to detect Unread emails that are in the 'Inbox'.

• Where it says: 'Select the folders to search' - how many folders are being searched?
• Click on 'Choose' button

The 'Inbox' should be selected, but check to see if any other folder or subfolder is also selected. If folders which receive moved emails are in that list as selected then:

• click on the square on the right to remove the 'tick',
• click on 'OK'
• click on 'Update'

Please report on findings.

As Rocky said to Muggsy (Buggs Bunny cartoon): "I don't know how yuz dunnit, but I know yuz dunnit". That's brilliant! Problem solved! Thanks a million, Toad-Hall! :D Curious to know how some of those subfolder got ticked. Also curious to know whether you're in Britain or Australasia.

Good to hear all is now working ok. I'm in Britain - England :)