Pre-fill composer with sender address

public/compose.html

@@ -10,13 +10,13 @@
 
 <form method="post" action="/compose">
 	<p>From:</p>
-	<input type="text" name="from">
+	<input type="email" name="from" value="{{.Message.From}}">
 	<p>To:</p>
-	<input type="text" name="to">
+	<input type="email" name="to" multiple>
 	<p>Subject:</p>
-	<input type="text" name="subject">
+	<input type="text" name="subject" value="{{.Message.Subject}}">
 	<p>Body:</p>
-	<textarea name="text" cols="80" rows="20"></textarea>
+	<textarea name="text" cols="80" rows="20">{{.Message.Text}}</textarea>
 	<br><br>
 	<input type="submit" value="Send">
 </form>

server.go

@@ -202,6 +202,11 @@ func handleGetPart(ctx *context, raw bool) error {
 func handleCompose(ectx echo.Context) error {
 	ctx := ectx.(*context)
 
+	var msg OutgoingMessage
+	if strings.ContainsRune(ctx.session.username, '@') {
+		msg.From = ctx.session.username
+	}
+
 	if ctx.Request().Method == http.MethodPost {
 		// TODO: parse address lists
 		from := ctx.FormValue("from")
@@ -220,12 +225,11 @@ func handleCompose(ectx echo.Context) error {
 			return echo.NewHTTPError(http.StatusForbidden, err)
 		}
 
-		msg := OutgoingMessage{
+		msg.From = from
-			from: from,
+		msg.To = []string{to}
-			to: []string{to},
+		msg.Subject = subject
-			subject: subject,
+		msg.Text = text
-			text: text,
+
-		}
 		if err := sendMessage(c, &msg); err != nil {
 			return err
 		}
@@ -239,7 +243,9 @@ func handleCompose(ectx echo.Context) error {
 		return ctx.Redirect(http.StatusFound, "/mailbox/INBOX")
 	}
 
-	return ctx.Render(http.StatusOK, "compose.html", nil)
+	return ctx.Render(http.StatusOK, "compose.html", map[string]interface{}{
+		"Message": &msg,
+	})
 }
 
 func New(imapURL, smtpURL string) *echo.Echo {

smtp.go

@@ -34,17 +34,17 @@ func (s *Server) connectSMTP() (*smtp.Client, error) {
 }
 
 type OutgoingMessage struct {
-	from string
+	From string
-	to []string
+	To []string
-	subject string
+	Subject string
-	text string
+	Text string
 }
 
 func (msg *OutgoingMessage) WriteTo(w io.Writer) error {
-	from := []*mail.Address{{"", msg.from}}
+	from := []*mail.Address{{"", msg.From}}
 
-	to := make([]*mail.Address, len(msg.to))
+	to := make([]*mail.Address, len(msg.To))
-	for i, addr := range msg.to {
+	for i, addr := range msg.To {
 		to[i] = &mail.Address{"", addr}
 	}
 
@@ -52,7 +52,9 @@ func (msg *OutgoingMessage) WriteTo(w io.Writer) error {
 	h.SetDate(time.Now())
 	h.SetAddressList("From", from)
 	h.SetAddressList("To", to)
-	h.SetText("Subject", msg.subject)
+	if msg.Subject != "" {
+		h.SetText("Subject", msg.Subject)
+	}
 
 	mw, err := mail.CreateWriter(w, h)
 	if err != nil {
@@ -68,7 +70,7 @@ func (msg *OutgoingMessage) WriteTo(w io.Writer) error {
 	}
 	defer tw.Close()
 
-	if _, err := io.WriteString(tw, msg.text); err != nil {
+	if _, err := io.WriteString(tw, msg.Text); err != nil {
 		return fmt.Errorf("failed to write text part: %v", err)
 	}
 
@@ -84,11 +86,11 @@ func (msg *OutgoingMessage) WriteTo(w io.Writer) error {
 }
 
 func sendMessage(c *smtp.Client, msg *OutgoingMessage) error {
-	if err := c.Mail(msg.from, nil); err != nil {
+	if err := c.Mail(msg.From, nil); err != nil {
 		return fmt.Errorf("MAIL FROM failed: %v", err)
 	}
 
-	for _, to := range msg.to {
+	for _, to := range msg.To {
 		if err := c.Rcpt(to); err != nil {
 			return fmt.Errorf("RCPT TO failed: %v", err)
 		}