BTW, would suggest not using your ISP's email service for personal use as it might tend to lock you in to them.
About 17 years ago I set up my own domain name for exactly that reason. I figured that if I changed ISPs I didn't want to have to change my email address.
Later when Gmail came out I got a Gmail account and started using it to fetch my domain email and to send it but didn't switch entirely to Gmail mostly because I was worried it would go away and back then you couldn't get an archive of your mail.
Now, I have less reason for the separate domain. I am not worried Gmail will vanish and, in any event, I can download my emails. And having it fetch my emails is sometimes tedious as it doesn't do it immediately. And, Godaddy was just about to start charging for email on accounts where they host the domain (until now it has been free).
So, the idea is just to get a bunch of gmail emails and forward all of them (except the investment account one) to my existing gmail account.
Currently leaning to this line up:
1. Investment account email that doesn't get forwarded to my main Gmail account. I keep it separate. On the fence whether to have one for those accounts or a separate one for each institution.
2. Email for personal friends/family and major accounts that already know my actual real life identity (this email has a variation of my nickname and last name).
3. Email for most vendors/merchants and maybe some long term forums (like ER but not the forum I went to just to get a specific question answered).
4. Everything else - most other forums, online sites, social media and places I just use a throwaway for. These are mostly things where if I had to change my email it would be fine.