After reading Antonio Prado’s Reverse DNS lookup for Italian Government’s mail exchangers post I got intrigued by the idea of checking how many of those Italian Government’s MX mail servers support STARTTLS.
STARTTLS “offers a way to upgrade a plain text connection to an encrypted (TLS or SSL) connection” (Wikipedia) and, when it’s implemented on the MX SMTP server, it allows a STARTTLS-aware user’s outbound mail server to encrypt the traffic toward the recipient’s server.
