Best privacy-focused email provider for custom domains

I was using protonmail since now but the email got closed due the spam and unusaul activity (SPAM)

Which other providers is better then protonmail to use as mail inbox and that doesnt affect the account to be closed

@papaku Proton didn't close you for a privacy reason, it closed you for volume. Any of them will -> Proton, Google, Fastmail, they all have the same spam tripwire. Switching provider without changing what set it off just resets the clock.

Two different jobs people mix up here:

Real inbox on your own domain -> Fastmail or Migadu. Boring, reliable, custom domains, they don't randomly nuke you. Mailbox.org if you want the EU/privacy lean.

Cold or bulk sending -> that should never run through your main inbox provider in the first place. Separate domain, a sending setup built for it, proper warmup. Push volume through your everyday inbox and you'll keep getting shut down no matter who hosts it.

So pick by what you're actually doing. Normal mail, Fastmail/Migadu and you're done. Outreach at volume, the provider isn't your problem, your sending setup is.

If ProtonMail flagged you for spam/abnormal activity, it’s usually more about sending patterns than the provider itself. You might want to try more established inbox options like Gmail or Outlook, or even Zoho Mail if you prefer something more flexible for business use.