Mullvad doing something — even if it's reknown — doesn't automatically make it's actions good.
Israel conducts surveillance of any VPN communications of any that exist in the region. This is fully legal there. This is a threat to privacy. You'd need to let me know how that isn't the case, not that X or Y company also hosts a server in the region.
Re: mail, not looking for perfect, just better than Gmail, ideally FOSS.
It's not operating in a bad country that makes the vpn bad, but the fact that the country is known for its surveillance of VPNs there that makes it bad.