Sometimes, when dragging messages, they drop into adjacent folders because mouse movement can be imprecise. My suggestion is to right-click the message instead and use the 'move to' option.

Thank you for your prompt reply. I have checked adjacent folders and the missing emails are not there. In any event this does not explain why messages already in the folders disappear for no apparent reason.

Maybe folder needs an index repair -try:

• right click on folder and select 'Properties'
• click on 'Repair Folder'
• click on OK

Confirm you have setting:

• View > Threads > All

Do you use 'Message Filters', so if new mail in Inbox was sent by eg: fred@email address .com then action would move email to 'Fred' folder. This would mean you would not need to move so many emails manually.

Do you have account setting to put replies in same folder as original email because this will also reduce a load of manual moves? Account Settings > Copies & Folders in 'Sent' section select checkbox 'Place replies in the folder of the message being replied to'

Thank you for your reply. I have already tried Repair Folder without success. I confirm that there is a tick against All Threads. I do not have message filters as I prefer to read the emails in my Inbox first, then file them in their folders when I have dealt with them. Since posting this query, I have counted the number of folders/sub folders affected and it is 24. This is out of a total of folders/sub folders a little in excess of 500 so it is only a small proportion which are currently affected. Of these some have had no new entries for a while whilst others are in regular use and it is these which drew my attention to the problem which I first noticed a few months ago. I was wondering whether there has been an update to the system which could account for the problem.

Further to my reply to you yesterday, I have been trying to pinpoint where exactly the problem is. I have on my webmail copies (in folders) of the emails which have gone missing from Thunderbird. I therefore transferred these back into the webmail Inbox and Thunderbird, in the usual way, copied them into the Thunderbird Inbox. I then set up new folders on both sites. Normally whether I use the webmail Inbox or Thunderbird Inbox to move emails, my actions are automatically reflected in the other system. With the Thunderbird Inbox open, I dragged and dropped the emails into the new folder. The emails duly disappeared from the Inbox but when I opened the new folder, they had not arrived there. I then went to the webmail folder and found that the emails were there. I repeated the procedure but with the webmail Inbox page open, transferring from the Inbox to the folder. Once again, the emails transferred satisfactorily on the webmail but failed to appear in the Thunderbird folder. It would seem therefore that the problem is the connection between Thunderbird’s Inbox and the folder. I do not know whether this further information will enable you to discover why things are going wrong.

Updated....Please check: The folders (24) are selcted to be subscribed.

• Right click on imap mail account name folder in Folder Pane and select 'Subscribe'
• Click on 'Refresh'
• Make sure all folders are selected and then click on 'Subscribe'
• Click on OK'

The folder(s) that are receiving the moved email -

• right click on folder and select 'Properties'
• Select: 'When getting new messages for this account, always check this folder'
• click on 'OK'

Also check

• Right click on imap mail account name folder in Folder Pane and select 'Settings'
• In 'Account Settings' select 'Synchronisation & Storage' for the account
• At top 'Message Synchronising'.....click on 'Advanced...'button
• Look for those 24 folders in the list and select the checkboxes so full copies get downloaded.
• Click on 'OK'

Exit Thunderbird, wait a few moments for background processes to complete and then restart Thunderbird.

Many thanks for your prompt response. I have carried out the procedures you suggested but unfortunately the emails are still

missing.

Further to our previous correspondence, I have identified another problem which may (or may not) be connected. When I receive an email with an attachment, there is no problem in opening the attachment and reading it but if I hit the "reply" button, access to the attachment immediately disappears. The common denominator is, of course, disappearing information. I have been using Thunderbird for many years and both these problems have only surfaced recently.

re :if I hit the "reply" button, access to the attachment immediately disappears.

Disappears from where ? The original received email should still have the attachment. Are you saying the original recieved email is losing attachments?

When you click on 'Reply' to respond - The attachment would not be attached in the 'Reply' Write window. This has been the case for a long time. Why ? because the person you are replying to was the person who sent you the attachment, so they do not need it sending back, they already have it.

If you chose 'Forward' then the attachment would be 'attached' because it is assumed you are not forwarding to the original sender - you would have used Reply for that. So you may be forwarding to someone who needs the attachment.

Thank you for your prompt response and explanation. I have gone back to the original received email and can confirm that the attachment is to be found there.

I am still unable to solve the reason why some emails are completely disappearing when I endeavour to move them into folders, whether new folders or those which already contain old emails.

re : I then set up new folders on both sites. Normally whether I use the webmail Inbox or Thunderbird Inbox to move emails, my actions are automatically reflected in the other system. With the Thunderbird Inbox open, I dragged and dropped the emails into the new folder. The emails duly disappeared from the Inbox but when I opened the new folder, they had not arrived there. I then went to the webmail folder and found that the emails were there.

This tells me you are using IMAP.

You say I then set up new folders on both sites. I may be misunderstanding you, but that sounds like you are creating the same folder name twice, once in Thunderbird and once in webmail. When you create a new folder in webmail account - let's call it 'Orders' as an example, you do NOT create that same folder in Thunderbird. You might need to check that 'Orders' is selected to be allowed to be seen in imap accounts. For example: gmail need the 'show in imap' checkbox selected. Then in Thunderbird, you subscribe to see that new folder 'Orders' folder which is on the server, so it appears in the IMAP account. OR if you created 'Orders' folder in Thunderbird imap account and it will appear in the webmail account. Then you make sure it is selected as subscribed and check the Properties of folder and the Account Synchronise and Storage options for the folder.

As I say I may have misunderstood you. Can you clarify this for me?

Folders can fail to show emails if they cannot synchronise with the server. When Thunderbird starts, it synchronises with server and displays what is in that folder on server. This maybe a Properties setting which does not allow new mail to be checked for that folder. But you say you have checked all those folders and that setting is selected.

Can you provide me with some visual information ? 1. Image showing Folder Pane in Thunderbird. Folders do need to be expanded if the problem folder is a subfolder - I need to see the hierarchy. Tell me which folder(s) is having a problem.

2. Image showing all folders and settings (need to see they are allowed for imap) in webmail account.

3. Image(s) showing that imap account name folder contents in profile name folder -

• Menu App icon > Help > More Troubleshooting Information
• Under 'Application Basics' half way - Profile Folder - click on 'Open Folder'

A new window opens showing contents of profile name folder.

• Exit Thunderbird now.

• Click on 'ImapMail' folder
• Click on the imap mail account name folder to see contents.

Make sure the 'View' is set to show details - name - modified date - size Expand window so you can show max amount of data. Post image showing all info and make sure I can see the directory. You may need to post several if scroll bar is required to see more. If you have folders with .sbd extension, these contain subfolders. If a problem folder is in a *.sbd folder, then click on *.sbd folder to see contents and post another image.

Whilst in this area, delete the *.msf index file of a problem folder. It will get rebuilt when you restart Thunderbird.

I am afraid this is all getting too technical for my eighty-four year old brain to cope with! I confirm that I am now using IMAP (although I never used to - it was set up originally as POP). I also confirm that I set up folders in both BT (my webmail) and Thunderbird. As I explained, I have over 500 folders so attached please find just a section with the folder properties for the one highlighted. As you can see, the number of messages is shown as 59 but when I open the folder, there is none on view. This means that earlier messages which used to appear no longer do and newer ones disappear when I try to transfer them from the Inbox to the folder. if all folders were similarly affected, I would think that the problem arises from my going over to IMAP but as only a small percentage are affected and they have all been treated the same, this does not appear to stand up.

OK re : number of messages is shown as 59 but when I open the folder, there is none on view.

If it says you have 59 but none display then it sounds like you have a filter operating on that folder. select that problem folder. Look at the 'Quick Filter Bar' Are any of those icons highlighted eg: 'pin' icon, 'show only unread' icon etc If any are highlighted, click on that icon to remove the highlight.

Thank you for your further advice. Where/How do I find the Quick Filter Bar? Sorry for being dim.

I've now found the bar but none of the icons is highlighted so I am afraid this does not solve my problem.

See if you have an invisible list: Select folder that says it has 59 There will be column headers eg: From, Subject,Date etc and on far right there is a 'select columns to display' icon. Click on that icon and you will get a drop down menu - near the bottom - click on 'Restore column order'

Thank you for your further attempts to assist me. I have done as you suggested but unfortunately the messages remain missing.

Further to previous correspondence, it appears definitely to be a problem with the actual folder(s). Today I received a new message from somebody whose previous emails have disappeared from the folder. As an experiment, I transferred the message to a folder which does not have a problem and it duly made the trip from the Inbox to the Folder. I then tried transferring the message from the wrong folder into the right one but, again, it disappeared en route.

re : I also confirm that I set up folders in both BT (my webmail) and Thunderbird.

I believe all your problems started when you began to incorrectly create folders in both locations. You only create the folder in one location. If you create it in webmail, then in Thunderbird you just subscribe to see it. If you create it in Thunderbird, then it will auto get created on server.

As you have an Imap maila ccount, then everything is stored on server.

Suggest you remove the imap mail account and then add it back again. Before removing the imap account -make a note of all the server settings and password etc. After removing account - exit Thunderbird. Wait a few moments for processes to complete. Start Thunderbird and add imap mail account. Then subscribe to see all the various folders on the server. Do this gradually as there are a lot to download.

I am not completely convinced that this is the solution to my problem. If it is, why are only a very small number of folders affected? If the switch to IMAP caused the problem, I would have expected all folders to react in the same way. Some of the affected folders were already on the system when I switched and some I have added since. Following on from this, as you told me I was in error in putting a new folder on both the server and Thunderbird, I ran a test. I set up a new folder on Thunderbird and then checked it had also appeared on the server, which it had (so far, so good!) From the server Inbox I then transferred an email to the new folder (successfully). I then went back into Thunderbird to see whether the email had successfully transferred there to find that not only the email had disappeared from the Inbox but the new folder had also disappeared! Not quite believing what I was seeing, I set up a second Test folder in Thunderbird and followed the same procedure with exactly the same results.