How to import mails to/Export mails from Icedove?

1. Download the following icedove add-on(ImportExporttools) from here.

2. Configure the add-on with your icedove client, steps are as follows.
Icedove --> Tools --> Add-ons

Now you will see a window like this ->


click on install button. Navigate to the downoalded ImportExportTools.xpi file and select it.

Now you will see a window like this ->

Once the "install" button enabled then click it. Your Icedove will automatically get restarted. Now you have the an option named "ImportExportTools"
in Icedove -> Tools ->

with sub options as show in the following image ->

So, Now if you want to export(backup) mails from icedove then select
Tools -> ImportExportTools -> Export options

If you want to import mails from some other backups(other mail client, but mbox format file) then select
Tools -> ImportExportTools -> Import options

Give a go through of all the available options in the Tools -> ImportExporttools and select the one which you want. Thats all now you are able to import/export backup your mails from icedove.

Note: Am using BOSS Linux 4.0, icedove version 3.0.7