[1]: IIRC, in my country the courts ruled that a) SMTP logs of sending an email are not sufficient technical proof of delivery and b) even if it was, that's not enough because you cannot be expected to regularly check your email account and read new mail. Things might be different in the U.S., that's why I'm asking.
Quick google found several public examples of such subpoenas, like https://cock.li/transparency/2015-12-15-subpoena/00-2015-12-...
And in any case, if the recipient fraudulently claimed that they had not received the subpoena they'd be committing crime.
Edit: Am I wrong? Is the subpoena I linked a fake?
> 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.
Edit: Why the downvotes? cmurf certainly needs to elaborate as to why either of those would affect the validity of the thousands of subpoenas that have been served over email.
But this is all beside the point, because an NSL could never be sent to anyone over internet postcard. Clinton discussed national secrets over email and look what happened to her.
The question is how things go when someone doesn't feel like playing ball. With email and not-signed-for letters there's no reasonable way to prove that the person saw the content. "Spam probably ate it." "It must have gotten lost in the mail." And so on.
So hand-served (and signed letter) subpoenas remain relevant for when people are dodging you. The fact that many people do respond to email subpoenas doesn't relate to whether non-respondents can be charged for their failure.
