[noisy_boy]

If it is just email, it is more ergonomic to setup a local POP client like Thunderbird to download the emails. You don't have to use it to send email, just configure once and bring it up regularly to fetch the emails. I have a full copy of my gmail mailbox this way (already moved banking/govt services to fastmail anyway).

[tempestn]

Yeah, this is what I do for email as well. Lets you seamlessly transition your backup to another service if/when you stop using gmail too. Though I use imap rather than pop, so that I don't end up with duplicates or other weirdness. (I keep incremental backups of the drive where the email is stored, so I'm not worried about a situation where both the cloud and backup copies get wiped.)

[NoZebra120vClip]

Here's the difference between IMAP and POP3. IMAP is a cloud service client, and POP3 is a store-and-forward, more or less. When you configure IMAP, you're operating on files on the server, and some or all of them may be cached, but the client will want to synchronize state with the server at all times. With POP3 you can specify "Leave on server" or "Delete from server". The POP client simply connects once and downloads everything (or everything that's new) and then you definitely have local copies of all those messages.

POP3 is good for use cases where you're rapidly migrating out and you want to wipe the messages clean, server-side. Or, if you believe the server will play hijinks with your messages or folders in some way, POP3 will give you a snapshot from time of download.