re :I've changed the file Sent to Sent.smf

If you accessed the profile folder and located the 'Sent' mbox file in the pop mail account - did you really change that mbox file to have .smf SMF is a file extension for an audio file in the MIDI format. or was that a typo and you actually changed it to .msf Netscape Mail (Mail Summary File) by NetscapeEach mail folder (Inbox, Sent, etc.) is stored as two files; one with no extension (e.g. INBOX), which is the mail file itself (in 'mbox' format), and one with an .MSF extension (e.g. INBOX.MSF), which is the index (Mail Summary File) to the mail file.

If you changed an mbox file as described above, that was not a good idea and is not suggested in any help advice.

In your profile folder mail account, where the emails are stored: 'Sent' file with no extension is an mbox file and it contains all your sent emails. It will also have a 'Sent.msf' file which is an indexing file used by Thunderbird, It does not contain any emails.

Please post an image showing the contents of your profile folder pop mail account, so I can see exactly what you done.

Thanks for the answer. I have not lost any info. I have copied the file.

My sent folder is almost empty now. I have moved all mail that has survived.

Posting the list of mail folder content.

Generally all your files look correct. But I can see evidense of potential issues that could arise and also some instances of compacting being aborted.

I notice that you have two particular files. nstmp Sept 2014 and nstmp -1 in Nov 2015

When you compact your folders, a copy is created, then the original file is rewritten and the copy deleted. If Thunderbird is interrupted during the compacting, it will abort, and the temporary file will not be deleted. nstmp and nstmp -1 are files showing a compaction process was interrupted.

You should be able to see those files as folders in your Folder Pane. It would be worth checking those folders to see if it contains any missing emails. You can move them back to the folder where they should be. If you are sure that all of those emails are just duplicates and none are missing emails, you can delete those files and their .msf files in your profile mail account folder. Remember Thunderbird must be closed when doing anything in the profile folders.

regarding 'Inbox': I notice that it has quite a size of 3.49 GB. or 3485 MB..in one single text file document. If you had to open that file, it might be difficult as the size is beyond or approaching the limits for most text editor programs. Unless you got a massive increase in emails, it is significantly larger than either of the other Inbox 2013/2014 folders. Maybe it has a load of 'marked as deleted' emails taking up space. I also notice that you created yearly folders for older Sent emails and so I'm presuming you are about to create an Inbox 2015 for last years emails. I would do this as soon as possible as any corruption on the Inbox file would cause havoc for you. It would be perhaps a good idea to also create an Inbox 2016 folder. After reading new incoming mail in Inbox, you could move it to the 'Inbox 2016' folder, thus keeping the actual 'Inbox' for receiving incoming mail.

My advice would be to create Inbox 2015 and Inbox2016 folders and then move all relevant emails into those folders, then delete anything you do not want so that the 'Inbox' is empty. When it is empty, right click on Inbox and select 'Compact' to remove all of those hidden 'marked as deleted' emails, reducing the size of your Inbox and regaining a load of space.

You can easily keep an eye on the 'Size' of your Folder Pane folders by enabling the following: 'View' > 'Layout' > select 'Folder Pane Columns' or 'Menu icon' > Options '> Layout' >select 'Folder Pane Columns'

Then - top right of Folder Pane, click on the small icon and select the 'Size' options. see image below.

Thank you for advice. My missing mails are not in nstmp folders. So it means they are not recoverable. Did I understand it right?

re :My missing mails are not in nstmp folders. then it is ok to delete those files in the Profile folder name mail account.

Last check to see if they are still in 'Sent' but hidden. All 'marked as deleted' emails will have number 0009. compacting looks for those marked emails and removes them. So, if there are some with that number then you can recover them.

in thunderbird

• Help > Troubleshooting Information
• click on 'Show folder'

a new window opens showing contents of profile folder name.

• close thunderbird now
• click on 'Mail' folder
• click on mail acount name folder

• Right click on 'Sent' (no extension) and open with Notepad

Each email will start with these lines: example: From - Tue May 12 13:19:12 2015 X-Mozilla-Status: 0001 X-Mozilla-Status2: 00800000

I need you to look for this line in particular: X-Mozilla-Status: If there are any with the number 0009. please edit the number to say 0001

Work through from top to bottom changing all back to 0001. It is much easier if you use the 'Edit' > 'Find' Save the 'Sent' file. close using top right X. then delete the 'Sent.msf' file.

Restart thunderbird.

Images below to help explain.