Update documentation for SMTPS support (outgoing)

README.md

@@ -20,11 +20,10 @@ produces mail.
 
 ## Main features
 
-* Supports incoming SMTPS/TLS (465), STARTTLS (587) and unencrypted SMTP (25)
+* Supports SMTPS/TLS (465), STARTTLS (587) and unencrypted SMTP (25)
 * Checks for sender, receiver, client IP
 * Authentication support with file (LOGIN, PLAIN)
 * Enforce encryption for authentication
-* Supports outgoing STARTTLS (587) and unencrypted SMTP (25)
 * Forwards all mail to a smarthost (GMail, MailGun or any other SMTP server)
 * Small codebase (smtp-proxy ~250 LoC, chrj/smtpd ~1200 LoC)
 * IPv6 support

smtp.go

@@ -297,7 +297,8 @@ func (c *Client) Data() (io.WriteCloser, error) {
 
 var testHookStartTLS func(*tls.Config) // nil, except for tests
 
-// SendMail connects to the server at addr, switches to TLS if
+// SendMail connects to the server at addr with TLS when port 465 or
+// smtps is specified or unencrypted otherwise and switches to TLS if
 // possible, authenticates with the optional mechanism a if possible,
 // and then sends an email from address from, to addresses to, with
 // message msg.