My view is -
Using your ISP's email is just asking for trouble.
It ties you in to them for starters. They can do also what they want. For example, some years go an acquaintance used
[email protected] as his business and personal mail address since he used them as the ISP. Out of the blue he got a message "we are discontinuing the vodafone.com email service, please make alternative arrangements within ... (some weeks)". The accounts were all disappearing forever.
Use a really big email service that is not going away - e.g. gmail (yes I know they read your email).
If you are at all serious and need to keep an address indefinitely register your own domain and then host the email where it suits you - e.g. with google ... you choose.
If you register a domain buy nothing else from the registrar except the domain. The same unfortunate gentleman mentioned above went with a package deal, domain, DNS, email, web site. Unfortunately he got into a commercial dispute. Of course they held the domain to ransom. It was all sorted out amicably after a couple of weeks and it resulted in nothing more than a useful lesson.