Are you talking about a pop or an imap mail account ?

If POP: Do you download emails and have settings to keep messages on server?

If IMAP: Imap accounts offer a type of virtual view of all emails stored on the server. The folders synchronise and so are really one and the same.

Logon to webmail account via a browser and report back on what you can see on the server.

You mention 'Boss', so sounds like a company, therefore it is likely you or boss or whomever is responsible for security of documentation, will have been making regular backups of the profile folder because emails are considered documents. Usually people keep contact information held in address books and so regular backups of profile would also keep a backup of all contact information.

Are you talking about a POP or IMAP mail account? Do you have a backup of the profile name folder? Or perhaps you have emails saved separately as .eml files as a backup ?

It says POP3 enabled? says 5120 quota mb. Does this mean they are saved somewhere? I know that no one has done any backups unless they are auto.

At this point in time - do not compact anything. If you know that compacting occured after the deletion, please let me know.

In Thunderbird 'Help' > 'Troubleshooting Information' click on 'Open Folder' button

a new window opens showing the contents of your 'profile name' folder.

Click on 'Mail' folder click on the pop mail account name folder to see contents.

Make sure you have the 'View' set to show 'Details' and the 'Size' column header visible. Expand window so everything is visible.

Post an image showing contents of the pop mail account folder. So we are talking about/seeing the same data.

If you have folders with a .sbd extension: click on the .sbd folder name Post image showing contents of each .sbd folder.

Here are the files it shows

You have an 'Inbox' mbox file of large size. Check to see if that Inbox has a load of hidden marked as deleted emails which you can recover.

Attempt to recover emails via Thunderbird. In Thunderbird

• 'Help' > 'Troublshooting Information'
• click on ' Open folder'

a new window opens showing profile folder name

• Close Thunderbird now - this is important
• click on 'Mail' folder
• click on pop mail account name that has missing emails.

you should see the 'Inbox' mbox file - it has no extension. See image below.

• Open the 'Inbox' mbox file using Notepad++

Emails are written to the file one after the other, so oldest will be at the top. Each email will start with these lines: this is an example

• From - Sun Dec 28 18:14:40 2014
• X-Mozilla-Status: 0001
• X-Mozilla-Status2: 00800000

• Use 'Edit' > 'Find'
• Start at the top, look for this line: X-Mozilla-Status: (not X-Mozilla-Status2:)

• Make sure each X-Mozilla-Status: has the number 0001
• edit the number as required working down through the document.
• Save the file.

The image you supplied also has:

• 'Inbox(2)' which has 0 size - so delete it.
• 'Inbox(s).msf - this is just an index file - no emails so delete it.
• if you see the 'Inbox.msf' file - I cannot see in image - delete it.

Note I'm not talking about those with date 2011, 2012 - not sure which folder they are in, but they have not been used recently.

• Restart Thunderbird.

If this recovers any emails in Inbox, then move those emails out of Inbox into suitable folders for organising and storage.

Image :

Images showing Examples of changing the X-Mozilla-Status

That inbox file is too large for notepad++ to open.

You may have to look for a text editor that can work with larger files. I can see from the image it says 1,337,776.... so I'm not entirely certain how large that could be, but it could be nearly 1.4GB

examples are: UltraEdit: http://www.ultraedit.com/

EmEditor https://www.emeditor.com/

HiEditor http://www.tucows.com/preview/510927/HiEditor