No, electronic documents are widely considered to be "papers" within the meaning of the 4th amendment. Your e-mails, sitting on your laptop, are definitely covered by the 4th amendment. The problem comes in when you send that e-mail in clear text over the internet, where a bunch of people at your ISP can see it, where a bunch of people at Google can see it, where a bunch of people at the recipient's ISP can see it, etc. You don't have an expectation of privacy when you take your private information and put it in the hands of others.
Whether it's an e-mail or ink on dead trees is irrelevant. If I printed out my e-mails and shipped them to Google, the government would be able to subpoena them without a warrant.
USPS is a third party. Why are physical letters protected?
At an organization like Google which is bound to have some internal controls, wouldn't an employee opening your email be analogous to the USPS opening an envelope?
Because there are explicit laws covering the protection of letters sent through USPS. We could make such laws covering ISPs, if our representatives wanted to.
I'm not talking about a letter intercepted en-route. I'm talking about a letter once it has been delivered to Google and is sitting on their premises, like your e-mail does once it's delivered via the SSL connection. The government can subpoena those papers just as they can subpoena the papers relating to your financials held by your accountants, etc.
"The problem comes in when you send that e-mail in clear text over the internet, where a bunch of people at your ISP can see it..."
So are you saying that if I encrypt my e-mail with the recipient's public PGP key, I have an expectation of privacy under the 4th Amendment? (Clearly, my intention in that case would be to make the message readable only to the recipient, not to his e-mail provider.)
Whether it's an e-mail or ink on dead trees is irrelevant. If I printed out my e-mails and shipped them to Google, the government would be able to subpoena them without a warrant.