People are often looking for ways to feel better knowing their trove of emails is safe. I’ve found a simple method that works reliably for me, and anyone can do!
First, install the Thunderbird mail client. It’s a free email tool that has a lot of settings for mail providers entered in to it already. If it doesn’t have settings for your email, it’s very similar to setting up a phone. I recommend setting up your email account as IMAP, because POP can sometimes erase messages from the server, and you may not intend to do that.
Anyway, once Thunderbird is installed and set up, to sync folders other than your inbox, simply click on them on the left hand side and give it some time for the folder to synchronize. It’s impossible to know how long this will take, due to variables like your internet connection or the size of your folder. Just watch the status bar in the bottom right to know when the sync is finished.
Once completed, create a folder where you would like your messages in that folder to be backed up. If you want, you could for instance create a folder on your desktop, and then create subfolders to match each and every one of your folders in your email account, and back them up one at a time.
Once the folder is created locally, simply highlight and drag emails from the Thunderbird client window to your local folder. To bring everything in the folder over at once, you can use Control A to “Select All,” or hold Shift and click the top, then bottom email. Once you drag everything to the local folder, you will see it create “.eml” files of every individual piece of mail. These are standard email files and are compatible with other email clients, like Outlook and the native Windows 10 Mail client.
If you wanted to move those emails into a new account, you could simply set up that account in Thunderbird, and drag files back to the folder in the other direction!