Important fix mentioned by The Dragon De Monsyne: the sendmail()

method does _not_ disconnect the connection when it throws a
SMTPHeloError!

Doc/lib/libsmtplib.tex

@@ -144,8 +144,7 @@ when at least one recipient was accepted).
 \item \exception{SMTPHeloError}
 
 The server didn't reply properly to
-the helo greeting.  The connection has
-been closed.
+the helo greeting.
 
 \item \exception{SMTPSenderRefused}