Interestingly, there's also this bit on their homepage[1]:
> In order for your subpoena / order to be processed, it must be sent to my lawyer. Do not send subpoenas to vc@cock.li or abuse@cock.li. Instead, E-mail or call me to request my lawyer's contact information.
It makes sense to have an established point of contact (which might be an email address) for LEAs if you're something like an ISP which regularly receives subpoenas. I'm more curious about subpoenas sent to individuals via email without any prior LEA contact.
It's also worth noting that the burden of proof for something like this is, at least in my country, on the sender's end, which is why all court communication is sent by registered post.
[1]: https://cock.li/abuse