Simply using a free email service _might_ cut it if you can live with your identity possibly being discovered

No log VPN paid for in monero + protonmail is probably sufficient to thwart most casual law enforcement / court involvement

If I wanted to go full blown tinfoil... I'd try and anonymously acquire a cheap used device via cash sale from a location without cameras, run tails on it, TOR + no log monero vpn + protonmail, then when finished thoroughly physically destroy the device to the level a 5 eyes TLA agency would for something they really didn't want recovered