From 55c347003093fa29fea0cc1123aa4760886a4a6c Mon Sep 17 00:00:00 2001
From: Robert Sesek <rsesek@bluestatic.org>
Date: Sat, 17 Dec 2016 18:22:14 -0500
Subject: [PATCH] Start saving SMTP messages in the maildrop.

---
 smtp.go        | 38 +++++++++++++++++++++++++++++++++++++-
 smtp/server.go |  8 ++++++++
 2 files changed, 45 insertions(+), 1 deletion(-)

diff --git a/smtp.go b/smtp.go
index fd071fd..24f635f 100644
--- a/smtp.go
+++ b/smtp.go
@@ -5,6 +5,9 @@ import (
 	"fmt"
 	"net"
 	"net/mail"
+	"os"
+	"path"
+	"strings"
 
 	"src.bluestatic.org/mailpopbox/smtp"
 )
@@ -50,6 +53,9 @@ func (server *smtpServer) TLSConfig() *tls.Config {
 }
 
 func (server *smtpServer) VerifyAddress(addr mail.Address) smtp.ReplyLine {
+	if server.maildropForAddress(addr) == "" {
+		return smtp.ReplyBadMailbox
+	}
 	return smtp.ReplyOK
 }
 
@@ -58,6 +64,36 @@ func (server *smtpServer) OnEHLO() *smtp.ReplyLine {
 }
 
 func (server *smtpServer) OnMessageDelivered(en smtp.Envelope) *smtp.ReplyLine {
-	fmt.Printf("MSG: %#v\n%s\n", en, string(en.Data))
+	maildrop := server.maildropForAddress(en.RcptTo[0])
+	if maildrop == "" {
+		// TODO: log error
+		return &smtp.ReplyBadMailbox
+	}
+
+	f, err := os.Create(path.Join(maildrop, en.ID+".msg"))
+	if err != nil {
+		// TODO: log error
+		return &smtp.ReplyBadMailbox
+	}
+
+	smtp.WriteEnvelopeForDelivery(f, en)
+	f.Close()
 	return nil
 }
+
+func (server *smtpServer) maildropForAddress(addr mail.Address) string {
+	domainIdx := strings.LastIndex(addr.Address, "@")
+	if domainIdx == -1 {
+		return ""
+	}
+
+	domain := addr.Address[domainIdx+1:]
+
+	for _, s := range server.config.Servers {
+		if domain == s.Domain {
+			return s.MaildropPath
+		}
+	}
+
+	return ""
+}
diff --git a/smtp/server.go b/smtp/server.go
index a574ef9..395a03d 100644
--- a/smtp/server.go
+++ b/smtp/server.go
@@ -2,6 +2,8 @@ package smtp
 
 import (
 	"crypto/tls"
+	"fmt"
+	"io"
 	"net"
 	"net/mail"
 	"time"
@@ -29,6 +31,12 @@ type Envelope struct {
 	ID         string
 }
 
+func WriteEnvelopeForDelivery(w io.Writer, e Envelope) {
+	fmt.Fprintf(w, "Delivered-To: <%s>\r\n", e.RcptTo[0].Address)
+	fmt.Fprintf(w, "Return-Path: <%s>\r\n", e.MailFrom.Address)
+	w.Write(e.Data)
+}
+
 type Server interface {
 	Name() string
 	TLSConfig() *tls.Config
-- 
2.22.5