What is 'Firebird' ? Are you talking about the 'Thunderbird' email client?

Exactly what is the question? You say 'Drafts is empty' which is a statement. No doubt you expected it to contain something. But that would depends upon several things.

You say 'After closing FireBird my draft was deleted', but was it saved in the first place?

You say you cannot offer more information, but you would need to supply a lot more information because believe it or not, we have no knowledge about your computer, type of account or set up etc.

At this point it is vital that you do not compact anything. Please provide the following Information so we can check all is set up correctly. I've also made some suggestions for checks and even a potential rescue.

What OS are you using ? What version of Thunderbird are you using ?

Did you get the download from the official website : https://www.thunderbird.net/en-US/thunderbird/all/ OR did you get a download/installation from Windows App Store or Snap or Flatpak or maybe portableapps ? That info is important because it also tells us where to expect the default location of your profile folders.

Are you talking about a POP or an IMAP mail account ? It's important to know because Imap synchs with server to show whatever is on server. That also means we would need to know what are your current settings for what to do with Drafts.

In 'Account Settings' > 'Copies & Folders' for the mail account What have you got selected for 'Drafts' ? Thunderbird would need to know what it's supposed to do with your draft emails. Upload an image showing what settings you are using.

In 'Settings' > 'Composition' Have you selected the checkbox to 'Auto save every X minutes' ? if yes how many minutes is set up ?

When you close a Write new message window you would get prompted to 'Save', 'Discard Changes' or 'Cancel'. Did you specifically click on 'Save' to save the 'Draft' email before closing the Write window? If no then it was not saved.

Is it possible you exited Thunderbird and forgot to save the email as a draft before exiting?

Did you by any chance accidentally or unknowlingly send the email? In which case it may be in the 'Sent' folder or if you used 'Send Later' it would be in the 'Outbox'. I have come across some people who have inadvertantly pressed the Enter/Return key and not realised they had also depressed the Ctrl key - those two keys together are the keyboard means of sending.

Have you checked to see if a filter is operating on the 'Drafts' folder ? Select 'Drafts' folder check the following: The 'Quick Filter' - are any of those icons enabled - they would show a blue bar. For example, if the 'pin' icon was selected then it may be applying a previous filter. If 'Show only unread mail' is selected it will show an empty view if there are no unread emails. So make sure none of those icons are selected.

Using 'Menu Bar' - View > Threads > select 'All (this is the default) - but is it selected? But it's also worth checking to see if you have inadvertantly set up email as ignored - very easy to do - the 'K' key on keyboard will set an email as ignored. You can check this by : View > Threads > also select 'Ignored threads' - if email displays a red circle icon in the threads column header then it was set up as ignored.

Did you check to see if the folder needed to be repaired ?

• Right click on Drafts folder and select 'Properties'
• click on 'Repair folder' button
• click on 'OK'

This action checks the contents of the mbox file that stores emails, and rebuilds the index file to match it.

Have you access that mail account email address via any other method which uses Imap connection such as phone, tablet, laptop or work computer or even directly via webmail using a browser? If you did and you deleted, moved, sent etc ect anything then it would update server and thus update the Thunderbird imap account.

Find out what is currently displayed in the 'Drafts' mbox file and see if you can recover an email which has been 'marked as deleted' and 'hidden'. Assuming you are using a Windows OS and assuming you got Thunderbird download /installtion from the official website:

• Exit Thunderbird if it's running - this is important

• In windows search type: %Appdata%
• Select the %Appdata% file folder option
• Select the 'Roaming' folder to see contents
• Select the 'Thunderbird' folder to see contents
• Select the 'Profiles' folder to see contents
• Select the 'profile name - various digits' folder to see contents

• IF POP account - Select the 'Mail' folder to see contents
• IF IMAP account - Select the 'ImapMail' folder to see contents

Look for a file called 'Drafts' - no extention (not Drafts.msf) Open the 'Drafts' file using a simple text editor eg: ' Notepad'

The oldest emails are at the top. Each email starts with the following lines - this is an example:

• From - Mon Aug 04 14:40:13 2025
• X-Mozilla-Status: 0001
• X-Mozilla-Status2: 00000000

If you see some email content - look for 'X-Mozilla-Status:' does it have this number 0001 ? If no, then please edit that number to say 0001

Work down through file and for each email you want to rescue Edit each X-Mozilla-Status: to say 0001 When finished, Save the file Then delete the index file of same name called 'Drafts.msf'

Finally start Thunderbird.

Wow*, thanks for this big answer. As you put a lot of effort in this response I'll try to make a good as well. I'll use it the next time.

It is indeed Thunderbird 140.3.1esr (32-Bit) on Windows 10 x64. I'm even not sure I closed Thunderbird, I wrote a very important letter, and when I came back to my PC, just the introducing of the response was there. Not able to revert or to restore anything. After chatting with GPT, it confirms that such bug is possible with Thunderbird.

I'm using IMAP and I think I got the app from the official website. I mean I've no special settings. In 'Account Settings' > 'Copies & Folders' are in both option the first is selected (my IMAP email adr). I've 'Auto save every 5 minutes'.

I've now rewritten the important email and send.

Cheers