Adds configuration for separate reply-to email header. (#10144)

* Adds configuration for separate reply-to email header.

* Changes config setting name.

* Using a separate variable and value in test.

* Updates for config pointer changes in another PR.

* Adds new key to test config. Adds default value.

model/config.go

@@ -1020,6 +1020,7 @@ type EmailSettings struct {
 	RequireEmailVerification          *bool
 	FeedbackName                      *string
 	FeedbackEmail                     *string
+	ReplyToAddress                    *string
 	FeedbackOrganization              *string
 	EnableSMTPAuth                    *bool
 	SMTPUsername                      *string
@@ -1075,6 +1076,10 @@ func (s *EmailSettings) SetDefaults() {
 		s.FeedbackEmail = NewString("test@example.com")
 	}
 
+	if s.ReplyToAddress == nil {
+		s.ReplyToAddress = NewString("test@example.com")
+	}
+
 	if s.FeedbackOrganization == nil {
 		s.FeedbackOrganization = NewString(EMAIL_SETTINGS_DEFAULT_FEEDBACK_ORGANIZATION)
 	}