Thunderbird was deleted from the server by default after receiving an email. After opening outlook, it was found that there was no email in the mailbox, which caused me to pay the boss's effort to restore it. Now we will summarize the restoration process, hoping to help people who encounter the same problems. 1. Download The importexporttools extension of Thunderbird. After installing and restarting Thunderbird, select the folder to be exported, select export, and then export the folder. By default, there is no extension, so you can manually add. mbox. 2. download imapsize, select Tools --- mbox2eml on the interface, and export it to a large number of EML files. 3. open Outlook Express, note that it is not outlook, and then drag all the files into the inbox, and all the emails will be imported to OE. 4. Select OE's "file"-export to import the email to outlook.