2 ms·
SMTP can be encrypted between servers (though not end-to-end) using STARTTLS, which is getting pretty common. If the mail's being relayed with STARTTLS, you wou
by _delirium 13y ago
SMTP can be encrypted between servers (though not end-to-end) using STARTTLS, which is getting pretty common. If the mail's being relayed with STARTTLS, you wouldn't be able to read it by tapping the wire. Instead, you'd need to get access to one of the relays, since each one decrypts the message before reencrypting it for the next hop (or you could manage to get yourself inserted as a relay).
Looking at a random email in my Gmail account from a different Gmail user, it looks like they do use SMTP, or at least they are adding headers as if it went by SMTP. But both ends of the SMTP are at the same IP address:
X-Received: from mr.google.com ([10.229.72.135])
by 10.229.72.135 with SMTP id m7mr3900891qcj.17.1370903118607 (num_hops = 1);
Mon, 10 Jun 2013 15:25:18 -0700 (PDT)