Very Bad: you@your-isp.com

Bad: you@platform-provider.com (gmail)

Good: you@your-lastname.me (or your-lastname.com)

your-lastname.me or your-lastname.com - is the domain you own.

Once you own your own domain and mailbox - just use platform providers (or ISP) for what they are useful for - as a temporary convenience tools. Always maintain backups of your mailboxes under your control.

If ISP or platform-provider will misbehave - scrap them for then better offering.