do not perform MX and SMTP checks at all when they are disabled

go.mod

@@ -20,7 +20,7 @@ require (
 	gitlab.com/etke.cc/go/mxidwc v1.0.0
 	gitlab.com/etke.cc/go/secgen v1.1.1
 	gitlab.com/etke.cc/go/trysmtp v1.0.0
-	gitlab.com/etke.cc/go/validator v1.0.3
+	gitlab.com/etke.cc/go/validator v1.0.4
 	gitlab.com/etke.cc/linkpearl v0.0.0-20221116205701-65547c5608e6
 	golang.org/x/net v0.2.0
 	maunium.net/go/mautrix v0.12.3

go.sum

@@ -99,8 +99,8 @@ gitlab.com/etke.cc/go/secgen v1.1.1 h1:RmKOki725HIhWJHzPtAc9X4YvBneczndchpMgoDkE
 gitlab.com/etke.cc/go/secgen v1.1.1/go.mod h1:3pJqRGeWApzx7qXjABqz2o2SMCNpKSZao/gXVdasqE8=
 gitlab.com/etke.cc/go/trysmtp v1.0.0 h1:f/7gSmzohKniVeLSLevI+ZsySYcPUGkT9cRlOTwjOr8=
 gitlab.com/etke.cc/go/trysmtp v1.0.0/go.mod h1:KqRuIB2IPElEEbAxXmFyKtm7S5YiuEb4lxwWthccqyE=
-gitlab.com/etke.cc/go/validator v1.0.3 h1:qkMskwtA3Uiv1q7HTlNZaaZcIJTO4mp2p0KZAl53Xmo=
+gitlab.com/etke.cc/go/validator v1.0.4 h1:2HIBP12f/RZr/7KTNH5/PgPTzl1vi7Co3lmhNTWB31A=
-gitlab.com/etke.cc/go/validator v1.0.3/go.mod h1:3vdssRG4LwgdTr9IHz9MjGSEO+3/FO9hXPGMuSeweJ8=
+gitlab.com/etke.cc/go/validator v1.0.4/go.mod h1:3vdssRG4LwgdTr9IHz9MjGSEO+3/FO9hXPGMuSeweJ8=
 gitlab.com/etke.cc/linkpearl v0.0.0-20221116205701-65547c5608e6 h1:+HDT2/bx3Hug++aeDE/PaoRRcnKdYzEm6i2RlOAzPXo=
 gitlab.com/etke.cc/linkpearl v0.0.0-20221116205701-65547c5608e6/go.mod h1:Dgtu0qvymNjjky4Bu5WC8+iSohcb5xZ9CtkD3ezDqIA=
 golang.org/x/crypto v0.0.0-20220518034528-6f7dac969898/go.mod h1:IxCIyHEi3zRg3s0A5j5BB6A9Jmi73HwBIUl50j+osU4=

smtp/server.go

@@ -13,12 +13,20 @@ import (
 	"gitlab.com/etke.cc/postmoogle/utils"
 )
 
-// ErrBanned returned to banned hosts
+var (
-var ErrBanned = &smtp.SMTPError{
+	// ErrBanned returned to banned hosts
+	ErrBanned = &smtp.SMTPError{
 		Code:         554,
 		EnhancedCode: smtp.EnhancedCode{5, 5, 4},
 		Message:      "please, don't bother me anymore, kupo.",
-}
+	}
+	// ErrNoUser returned when no such mailbox found
+	ErrNoUser = &smtp.SMTPError{
+		Code:         550,
+		EnhancedCode: smtp.EnhancedCode{5, 5, 0},
+		Message:      "no such user here, kupo.",
+	}
+)
 
 type mailServer struct {
 	bot     matrixbot

smtp/session.go

@@ -56,15 +56,13 @@ func (s *incomingSession) Rcpt(to string) error {
 	}
 	if !domainok {
 		s.log.Debug("wrong domain of %s", to)
-		s.ban(s.addr)
+		return ErrNoUser
-		return ErrBanned
 	}
 
 	roomID, ok := s.getRoomID(utils.Mailbox(to))
 	if !ok {
 		s.log.Debug("mapping for %s not found", to)
-		s.ban(s.addr)
+		return ErrNoUser
-		return ErrBanned
 	}
 
 	validations := s.getFilters(roomID)
@@ -166,7 +164,7 @@ func validateEmail(from, to string, log *logger.Logger, options utils.IncomingFi
 	enforce := validator.Enforce{
 		Email: true,
 		MX:    options.SpamcheckMX(),
-		SMTP:  options.SpamcheckMX(),
+		SMTP:  options.SpamcheckSMTP(),
 	}
 	v := validator.New(options.Spamlist(), enforce, to, log)
 

vendor/gitlab.com/etke.cc/go/validator/emails.go

@@ -35,34 +35,35 @@ func (v *V) Email(email string) bool {
 		}
 	}
 
-	if v.emailMX(email) {
+	if v.enforce.MX {
+		if v.emailNoMX(email) {
 			return false
 		}
+	}
 
-	smtpCheck := !v.emailSMTP(email)
 	if v.enforce.SMTP {
-		return smtpCheck
+		if v.emailNoSMTP(email) {
+			return false
+		}
 	}
 
 	return true
 }
 
-func (v *V) emailMX(email string) bool {
+func (v *V) emailNoMX(email string) bool {
 	at := strings.LastIndex(email, "@")
 	domain := email[at+1:]
 
 	nomx := !v.MX(domain)
 	if nomx {
 		v.log.Info("email %s domain %s invalid, reason: no MX", email, domain)
-		if v.enforce.MX {
 		return true
 	}
-	}
 
 	return false
 }
 
-func (v *V) emailSMTP(email string) bool {
+func (v *V) emailNoSMTP(email string) bool {
 	client, err := trysmtp.Connect(v.from, email)
 	if err != nil {
 		if strings.HasPrefix(err.Error(), "45") {

vendor/modules.txt

@@ -127,7 +127,7 @@ gitlab.com/etke.cc/go/secgen
 # gitlab.com/etke.cc/go/trysmtp v1.0.0
 ## explicit; go 1.18
 gitlab.com/etke.cc/go/trysmtp
-# gitlab.com/etke.cc/go/validator v1.0.3
+# gitlab.com/etke.cc/go/validator v1.0.4
 ## explicit; go 1.18
 gitlab.com/etke.cc/go/validator
 # gitlab.com/etke.cc/linkpearl v0.0.0-20221116205701-65547c5608e6