Update mail defaults for local sending (#4218)

Update mail config defaults to be preconfigured for sending emails on
local MTA on port 25, without encryption nor authentication.

This should be suitable default for selfhosting and local dev
environments

cmd/serve.go

@@ -203,7 +203,7 @@ func init() {
 	flags.String("mail-noreply-address", "", "mail address used for sending mail as a noreply (forgot passwords for example)")
 	checkNoErr(viper.BindPFlag("mail.noreply_address", flags.Lookup("mail-noreply-address")))
 
-	flags.String("mail-noreply-name", "", "mail name used for sending mail as a noreply (forgot passwords for example)")
+	flags.String("mail-noreply-name", "My Cozy", "mail name used for sending mail as a noreply (forgot passwords for example)")
 	checkNoErr(viper.BindPFlag("mail.noreply_name", flags.Lookup("mail-noreply-name")))
 
 	flags.String("mail-reply-to", "", "mail address used to the reply-to (support for example)")
@@ -212,7 +212,7 @@ func init() {
 	flags.String("mail-host", "localhost", "mail smtp host")
 	checkNoErr(viper.BindPFlag("mail.host", flags.Lookup("mail-host")))
 
-	flags.Int("mail-port", 465, "mail smtp port")
+	flags.Int("mail-port", 25, "mail smtp port")
 	checkNoErr(viper.BindPFlag("mail.port", flags.Lookup("mail-port")))
 
 	flags.String("mail-username", "", "mail smtp username")
@@ -224,7 +224,7 @@ func init() {
 	flags.Bool("mail-use-ssl", false, "use ssl for mail sending (smtps)")
 	checkNoErr(viper.BindPFlag("mail.use_ssl", flags.Lookup("mail-use-ssl")))
 
-	flags.Bool("mail-disable-tls", false, "disable starttls on smtp")
+	flags.Bool("mail-disable-tls", true, "disable starttls on smtp")
 	checkNoErr(viper.BindPFlag("mail.disable_tls", flags.Lookup("mail-disable-tls")))
 
 	flags.String("mail-local-name", "localhost", "hostname sent to the smtp server with the HELO command")