If you would like to export your emails to EML, Mbox, or Maildir format, you can easily do that using Webmail.
For this, just access Webmail and select all the emails which you would like to export. You can use a Select button to do it quicker:
Once selected, click on More, then Download, and choose the format:
After that's done, an archive of all of your emails will be downloaded to your computer.
NOTES:
You can download EML file only for 1 email at a time
If you choose Mbox or Maildir, you will receive a .zip file containing the emails in the chosen format