accept empty from-address in SPF fixes #603

(cherry picked from commit 691ba53)

internal/check/spf/spf.go

@@ -314,6 +314,12 @@ func (s *state) CheckConnection(ctx context.Context) module.CheckResult {
 		return module.CheckResult{}
 	}
 
+	if s.msgMeta.OriginalFrom == "" {
+		s.skip = true
+		s.log.Println("sender address is empty")
+		return module.CheckResult{}
+	}
+
 	mailFrom, err := prepareMailFrom(s.msgMeta.OriginalFrom)
 	if err != nil {
 		s.skip = true

tests/smtp_test.go

@@ -218,6 +218,9 @@ func TestCheckSPF(tt *testing.T) {
 	conn.Writeln("RSET")
 	conn.ExpectPattern("250 *")
 
+	conn.Writeln("MAIL FROM:<>")
+	conn.ExpectPattern("250 *")
+
 	conn.Writeln("MAIL FROM:<[email protected]>")
 	conn.ExpectPattern("551 5.7.0 *")
 
@@ -453,7 +456,7 @@ func TestCheckAuthorizeSender(tt *testing.T) {
 						auth_normalize precis_casefold
 						user_to_email static {
 							entry "test-user1" "[email protected]"
-							entry "test-user2" "é@example1.org" 
+							entry "test-user2" "é@example1.org"
 						}
 					}
 				}