Sometimes, when you retrieve emails in your favorite mail client, the server may disconnects. In some cases you get 2 times (or more) the same messages and you are then obliged to remove them manually.
Fortunately, if you use Thunderbird, there is a solution to avoid such duplication upon reception.
Just go into Thunderbird options (Tools -> Options (Windows).
Click on the icon "Advanced" then click the button "Configuration Editor" under the "General" tab.
You will then have access to a list of options (just as with the about: config in Firefox).
Look for one that is called mail.server.default.dup_action (by typing in the filter). Right click on this key and change the value through the following figure:
- 0 if you want to load the duplicate mails as usual
- 1 if you want to delete automatically (and directly) emails duplicated once they have been approved.
- 2 if you want to duplicate the mail in the trash
- 3 if you want to mark the duplicate mails as "already read"