Before I close my google account, I need to visit any websites I registered with that address and change them. Is there a tool that can scan my email and give me a list of deduplicated domains and contacts?
Unfortunately I delete most email so I expect some surprises in the future but I have time for this now.
As you switch, I would highly recommend you purchase a domain for yourself, and redirect email from it to your new provider. This separates your “identity” from your email host, so you can switch the latter without having to go through this process again.