I recently switched to a new company. As I am the sales head, I receive a lot of emails to look at daily. Earlier I was using Mac Thunderbird as my daily email client but now here it is mandatory to use Apple Mail. So I need to switch from Mac Thunderbird to Apple Mail. The only thing that I require is to backup all my emails before I make the switch so that I don't loose any while migration. I am looking for a quick backup solution that won't take long to do the backup procedure.
Thanks for the help in advance.