For me the big pain is moving off all the stuff referencing a *@gmail.com address to something else. There is no real such thing as 'phone number portability' in email. Even if you forward everything, you can still lose the forwarding.
The 'phone number portability' of email is you owning the domain, and pointing the mx record to whatever mail provider you like. To switch providers you simply register an account somewhere else and change your dns record.
By starting with an "@gmail.com" address you willingly give that up, but that's not the system's fault.
I did this a few years ago. I don't know if I'm 100% transitioned but I'm just about.
I setup the forward from <name>@gmail.com to <name>@<mydomain>. I then flagged things that are coming from gmail and slowly updated addresses on those websites to point at <name>@<mydomain>. You don't have to be in a hurry to get it done you just have to be working towards the end goal.
I set up my new domain email address as an email forwarder to Gmail, and used it like that for nearly a year. When signing up for things, I'd just use that address instead of the Gmail address.
When I moved to FastMail, I set up that email address to go to FastMail instead. Most of my inbound mail instantly came with it. It's been a couple weeks, I still get stuff on my Gmail. So I check it once or twice a day still at the moment, and when I get something from some website, I go log into that account, and change my email address.
Fastmail can also pull in from your gmail account. You could do that and tag the emails. It might be a good time saver and save you from having to do manual checks.
Yeah, I know. But my concern is if it's 'too easy' to just handle my Gmail messages in Fastmail that I'll procrastinate changing over the accounts properly.
Once I get down to a minimal amount I'll forward and tag.
