If target is not specified use the server in MX record

src/cmd/enum/smtp.go

@@ -38,9 +38,8 @@ func init() {
 	smtpCmd.Flags().StringVarP(&smtpOptions.Domain, "domain", "d", "", "Targeted domain ")
 	smtpCmd.Flags().StringVarP(&smtpOptions.Mode, "mode", "m", "", "RCPT, VRFY, EXPN (default: RCPT)")
 	smtpCmd.Flags().StringVarP(&smtpOptions.Users, "user", "u", "", "Username or file containing the usernames")
-	smtpCmd.Flags().StringVarP(&smtpOptions.Target, "target", "t", "", "Host pointing to the OWA service")
+	smtpCmd.Flags().StringVarP(&smtpOptions.Target, "target", "t", "", "Host pointing to the SMTP service. If not specified, the first SMTP server in the MX record will be targeted.")
 	smtpCmd.Flags().IntVar(&smtpOptions.Thread, "thread", 2, "Number of threads")
 	smtpCmd.MarkFlagRequired("user")
-	smtpCmd.MarkFlagRequired("target")
 	smtpCmd.MarkFlagRequired("domain")
 }

src/modules/smtp/userEnum.go

@@ -3,6 +3,7 @@ package smtp
 import (
 	"GoMapEnum/src/utils"
 	"fmt"
+	"net"
 	"strconv"
 	"strings"
 	"time"
@@ -13,6 +14,15 @@ import (
 func PrepareSMTPConnections(optionsInterface *interface{}) {
 	options := (*optionsInterface).(*Options)
 	options.connectionsPool = make(chan *smtp.Client, options.Thread)
+
+	if options.Target == "" {
+		mxrecords, err := net.LookupMX(options.Domain)
+		if err != nil {
+			options.Log.Fatal("Not able to retrieve the MX for the domain " + options.Domain)
+		}
+		options.Target = mxrecords[0].Host
+	}
+
 	var nbConnectionsRequired int
 	nbConnectionsRequired = options.Thread
 	if len(options.UsernameList) < options.Thread {