Global rules must not filter mail by default, requiring the user to opt out of the filtering. No person should be made afraid to send legitimate, desired E-mail. Regulations must create no fear in the senders of legitimate mail that is desired by its recipients. If fear stops an otherwise legitimate message from being sent, the law has gone too far. However the internet and E-mail are to be regulated, control should wherever possible be distributed rather than centralized.
Centralized control presents a temptation for overcontrol and is a risk to free expression.
Such liability would leave them no choice but to engage in draconian oversight over all their users activities. However, a large proportion of E-mail and other traffic flows with the sender unaware of the geographic destination, and the burden of checking would be a significant one. States, on the other hand, can punish parties outside their state if given the power to make such laws. If a law provides individuals the power to sue over the receipt of certain communications, this is still government regulation of those communications. It's probably a better form of that regulation, but should not be mistaken for a non-governmental method.