Here are the steps I've been following:

1) Sign up for Fastmail.

2) Sync all mail from GMail account to Fastmail (via the Fastmail web UI; you grant FM access to your GMail data through OAuth - once sync is complete you can revoke this access).

3) Set up an auto-forward rule in GMail for all incoming mail to go to your Fastmail address.

4) Set up a rule in Fastmail to put all incoming mail sent to your GMail address into a separate folder (or labeled with a special label if you're signed up for Fastmail's label beta). Any time you get email in that folder, that's a task for you to either unsubscribe or update the corresponding account to your new email address.

I'm currently in month #10 of migration. Most commonly used accounts were updated during the first couple of weeks. But be careful that the tail of services that are still configured to use your old email address tends to be long, and in my experience those are some of the more important emails that you don't want to miss. The ones that are only sent once every couple years.

Also, it really helps if you've been using GMail with a personal domain name (e.g. through Google Apps). In this case migrating is a matter of pointing the MX DNS records to Fastmail's servers. Bonus points: Fastmail allows wildcard recipients, so if you prefer to have unique addresses for each service you sign up for, you don't even need to set up a separate [email protected] alias. Just register with <whatever>@example.com and you'll get all email delivered to that address in your inbox, and you'll be able to specify it as the sender's address if you decide to reply to some of those mails. Having a separate email address for each web service also makes looking up who leaked what on haveibeenpwned.com more fun.

And most importantly:

0) Get your own domain and set up MX record to fastmail servers

This way if you ever migrate again, you will not need to do it all over again. One word of advice - keep your registrar login and emails associated with the domains _not_ on your domain, otherwise it is going to present a problem should you ever need to fix anything related to domains.

And keep addresses, phone numbers, alternative emails, payment details up to date with your domain registrar.

Recently my provider decided to randomly cancel my domain, getting it back from transfer with everything out of date was painful.

That is a great advice. One of the registrars has been sending verification messages for one of my oldest domains to the mail account that I do not use anymore and one day they stopped serving DNS for it. I had an access to the old mail account still but if I had not, that would have been an arduous process indeed!

Then you are pushing the problem to someone else to manage the domains right? How do you set this up?

OK, I think the other reply missed your question (if I am reading this correctly).

Basically, if you register your domain through namecheap, then after setting up email at *@ximeng.net, don't update your email address to be [email protected] when changing the rest of your accounts. Reason being, if for some reason there is a problem with the domain, you don't want your only means of fixing that problem to potentially be invalid.

Therefore it wouldn't be a bad idea to keep the account associated with your registrar still on the original Gmail address (or if you are really paranoid, create a new email address through someone like protonmail just for your registrar account).

Right, that is what I meant - you’re then pushing the risk to the management of that secondary protonmail or gmail account. So you basically always rely on a third party to manage the registrar account.

Oh I see. I agree that it is a risk, so - in the vein of another advice in this thread - if you have a co cern about third party email provider, update your domain records to another provider.

Not sure I understand the question.

I have to manage a domain and have a basic understanding of how DNS works, that is unavoidable.

DNS is a bit complicated to describe in short reply but on a very high level: say I register a domain example.com. Registrars usually give you an interface to manage DNS where you can set A records (association with IP), you basically put there 2-5 IP addresses of the DNS servers serving your domain. You can also setup MX records that are used to resolve mail servers for your domain. Setting up fastmail is simple: you tell them that you want them to serve mail for example.com and setup couple of MX records pointing to the Fastmail servers (they give you the full host names).

Sorry I wasn’t clear - basically my concern was that you still have a dependency on a third party email address.

I set up my own domain, and forwarded emails from it to my Gmail account. Over a year and a half, every time I logged into something, I updated the email address to my own.

Eventually, when I jumped to FastMail, I repointed my domain name to it, and most of my new emails started coming over automatically, since the email address is now something I control. I monitored Gmail for a while regularly to catch straggler services. (I chose not to forward to avoid complacency with stuff going to Gmail before reaching my FastMail account.)

I did this recently. It's pretty straightforward.

First, do a one-time import from Gmail. Fastmail has an import tool that does this over OAuth. Took me ~45 minutes to import ~50,000 emails.

Next, setup IMAP and SMTP on Fastmail for your Gmail account. This way, you can continue to receive and reply to emails sent to Gmail, using Fastmail as the client. When replying to an email, Fastmail defaults to the right sender (identity) based on whom the email is sent to ([email protected] or [email protected]).

An alternative is to setup email forwarding in Gmail, so you get a copy of emails sent to your old address.

If you don't have a custom domain, I highly recommend getting one and use that going forward. There might come a day when you want to migrate off Fastmail. With a custom domain, you just need to update the MX records.

Get your own domain, use it for all your email, and in five or so years gmail will be nothing but spam, basically.

which ironically, is the 5yrs it take for gmail/yahoo to not threat your domain outgoing email as spam.

I've never had a problem with gmail recipients since setting up DKIM, SPF, etc. There is an incompetent rinkydink shop running IT for the Irish government ( Topsec - https://www.topsec.com/ )that blocks ANY email from namecheap DNS which is really annoying, though.

FastMail can pull from gmail. My account pulls from all emails I use minus work and can send on those addresses so. It also supports having a different signature depending on which address I'm sending from.

See https://www.fastmail.com/help/account/migratetofastmail.html

No connection to them, just a happy customer!

a bit like a physical address - forward the mail on for x months and then cut off completely

That's what I did and it worked well for me for the most part. I ended up keeping Gmail around for the occasional service that doesn't work well with Fastmail. Off the top of my head I've had issues with:

- Frontier

- Green Man Gaming

- Paperspace

- Rainway

- SquareTrade

Late but essentially what the others said. Additionally I would point out that I migrated my accounts whenever I used them and noticed I logged in - so really piecewise.

On top, I had some burts of motivation to step through my password manager vault occasionally and update accounts I don't log in to too much.

I went through all accounts in my password manager and changed it. Not so bad. It doesn't need to be done quickly.

I would make this Step #1 to the 5 or 6-step processes outlined above. Gets most of the important migration out of the way with a little work the first day.