Implement Reply-To functionality for automatically adding sender address

README.md

@@ -20,6 +20,7 @@ API that can be accessed via JavaScript `Fetch()` or `XMLHttpRequest`.
 * reCaptcha v2 support
 * Form field type validation (text, email, number, bool)
 * Confirmation mail to poster
+* Custom Reply-To header based on sending mail address
 
 ### Planed features
 
@@ -95,6 +96,9 @@ the JSON syntax of the form configuration is very simple, yet flexible.
       "message"
     ]
   },
+  "replyto": {
+    "field": "email"
+  },
   "confirmation": {
     "enabled": true,
     "rcpt_field": "email",
@@ -166,6 +170,8 @@ the JSON syntax of the form configuration is very simple, yet flexible.
         * `name (type: string)`: Field validation identifier
         * `type (type: string)`: Type of validation to run on field (text, email, nummber, bool)
         * `required (type: boolean)`: If set to true, the field is required
+* `replyto (type: struct)`: The struct for the reply to configuration
+    * `rcpt_field (type: string)`: Name of the form field holding the reply-to mail sender address
 * `server (type: struct)`: The struct for the forms mail server configuration
     * `host (type: string)`: Hostname of the sending mail server
     * `port (type: uint32)`: Port to connect to on the sending mail server

api/sendform.go

@@ -59,6 +59,12 @@ func (r *Route) SendForm(c echo.Context) error {
 	mailMsg.SetHeader("From", sr.FormObj.Sender)
 	mailMsg.SetHeader("To", sr.FormObj.Recipients...)
 	mailMsg.SetHeader("Subject", sr.FormObj.Content.Subject)
+	if sr.FormObj.ReplyTo.Field != "" {
+		sf := c.FormValue(sr.FormObj.ReplyTo.Field)
+		if sf != "" {
+			mailMsg.SetHeader("Reply-To", sf)
+		}
+	}
 
 	mailBody := "The following form fields have been transmitted:\n"
 	for _, k := range sr.FormObj.Content.Fields {

form/form.go

@@ -23,9 +23,12 @@ type Form struct {
 	Domains    []string `fig:"domains" validate:"required"`
 	Id         string   `fig:"id" validate:"required"`
 	Recipients []string `fig:"recipients" validate:"required"`
-	Secret     string   `fig:"secret" validate:"required"`
-	Sender     string   `fig:"sender" validate:"required"`
-	Server     struct {
+	ReplyTo    struct {
+		Field string `json:"field"`
+	}
+	Secret string `fig:"secret" validate:"required"`
+	Sender string `fig:"sender" validate:"required"`
+	Server struct {
 		Host     string `fig:"host" validate:"required"`
 		Port     int    `fig:"port" default:"25"`
 		Username string

server/server.go

@@ -17,7 +17,7 @@ import (
 )
 
 // VERSION is the global version string contstant
-const VERSION = "0.2.2"
+const VERSION = "0.2.3"
 
 // Srv represents the server object
 type Srv struct {