-2.3 Use of EHLO/HELO [3.2]
---------------------------
-
-[Client MTAs should always start with EHLO, not HELO.]
-
-Exim sends EHLO only when it finds the string "ESMTP" in an SMTP greeting
-message. If EHLO is refused with a 5xx return code, it then reverts to HELO as
-required, but it does not contain logic for converting to HELO on other errors
-such as loss of connection or timeout after EHLO. That is one reason why it
-doesn't always send EHLO; there are reported to be ancient SMTP servers out
-there which collapse on receiving EHLO. (There is also at least one server
-whose banner reads "<host name> ignores ESMTP", but it is RFC 821 compliant in
-that it responds with 5O0 to EHLO, so Exim successfully reverts to HELO.)
-
-
-2.4 Closing the connection [4.1.1.10]