diff --git a/models/user/email_address_test.go b/models/user/email_address_test.go
index 4ced7c7f3d5..15e2d84b2e9 100644
--- a/models/user/email_address_test.go
+++ b/models/user/email_address_test.go
@@ -151,16 +151,28 @@ func TestListEmails(t *testing.T) {
 
 func TestEmailAddressValidate(t *testing.T) {
 	cases := map[string]bool{
-		"":                   false,
-		"root@localhost":     true,
-		"user@[192.168.1.2]": true,
-		"@a":                 false,
-		"abc@gmail.com":      true,
-		"abc@gmail.com\n":    false,
+		"":   false,
+		"@a": false,
+
+		// "_" shouldn't appear in domain but can appear in hostname, since we can't stop site admins from doing so, just accept it
+		"root@local_host": true,
+		"root@localhost":  true,
+		"root@LOCALHOST":  true,
+
+		"user@[192.168.1.2]":  true,
+		"user@[IPv6:FFff::1]": true,
+
+		"abc@gmail.com":   true,
+		"abc@gmail.com.":  false,
+		"abc@gmail.com-":  false,
+		"abc@gmail.com\n": false,
+		"abc@gmail..com":  false,
+		"abc@gmail com":   false,
+		"abc@gmail*com":   false,
+
 		"Foo <foo@bar.com>":  false,
 		"abc@gmail.com (x)":  false,
-		"jürgen@example.com": false,
-		"a@foo_bar.com":      false,
+		"jürgen@example.com": false, // utf8 address is not supported yet
 	}
 	for tc, isValid := range cases {
 		t.Run(tc, func(t *testing.T) {
diff --git a/modules/private/manager.go b/modules/private/manager.go
index 559de8dc577..58cb72b4163 100644
--- a/modules/private/manager.go
+++ b/modules/private/manager.go
@@ -38,14 +38,14 @@ func ReloadTemplates(ctx context.Context) ResponseExtra {
 
 // FlushOptions represents the options for the flush call
 type FlushOptions struct {
-	Timeout     time.Duration
+	Timeout     int64
 	NonBlocking bool
 }
 
 // FlushQueues calls the internal flush-queues function
 func FlushQueues(ctx context.Context, timeout time.Duration, nonBlocking bool) ResponseExtra {
 	reqURL := setting.LocalURL + "api/internal/manager/flush-queues"
-	req := newInternalRequestAPI(ctx, reqURL, "POST", FlushOptions{Timeout: timeout, NonBlocking: nonBlocking})
+	req := newInternalRequestAPI(ctx, reqURL, "POST", FlushOptions{Timeout: int64(timeout), NonBlocking: nonBlocking})
 	if timeout > 0 {
 		req.SetReadWriteTimeout(timeout + 10*time.Second)
 	}
diff --git a/modules/validation/helpers.go b/modules/validation/helpers.go
index 30b8484d0d7..9a4db7014e7 100644
--- a/modules/validation/helpers.go
+++ b/modules/validation/helpers.go
@@ -14,8 +14,6 @@ import (
 
 	"gitea.dev/modules/glob"
 	"gitea.dev/modules/setting"
-
-	"golang.org/x/net/idna"
 )
 
 type globalVarsStruct struct {
@@ -24,6 +22,8 @@ type globalVarsStruct struct {
 	invalidUsernamePattern  *regexp.Regexp
 	validBadgeSlugPattern   *regexp.Regexp
 	invalidBadgeSlugPattern *regexp.Regexp
+	validEmailHostName      *regexp.Regexp
+	validEmailHostIP        *regexp.Regexp
 }
 
 var globalVars = sync.OnceValue(func() *globalVarsStruct {
@@ -33,6 +33,8 @@ var globalVars = sync.OnceValue(func() *globalVarsStruct {
 		invalidUsernamePattern:  regexp.MustCompile(`[-._]{2,}|[-._]$`), // No consecutive or trailing non-alphanumeric chars
 		validBadgeSlugPattern:   regexp.MustCompile(`^[A-Za-z0-9][A-Za-z0-9._-]*$`),
 		invalidBadgeSlugPattern: regexp.MustCompile(`[-._]{2,}|[-._]$`),
+		validEmailHostName:      regexp.MustCompile(`^[a-zA-Z0-9][-.\w]*$`),
+		validEmailHostIP:        regexp.MustCompile(`(?i)^\[([0-9.]+|ipv6:[0-9a-f:.]+)\]$`),
 	}
 })
 
@@ -124,10 +126,12 @@ func IsEmailAddressValid(email string) bool {
 		return false
 	}
 	_, domain, _ := strings.Cut(email, "@")
-	if strings.HasPrefix(domain, "[") {
-		// address like "foo@[192.168.1.2]"
-		return true
+	if !globalVars().validEmailHostName.MatchString(domain) && !globalVars().validEmailHostIP.MatchString(domain) {
+		return false
 	}
-	_, err = idna.Registration.ToASCII(domain)
-	return err == nil
+	if strings.HasPrefix(domain, "-") || strings.HasSuffix(domain, "-") ||
+		strings.HasPrefix(domain, ".") || strings.HasSuffix(domain, ".") {
+		return false
+	}
+	return true
 }
diff --git a/routers/private/manager.go b/routers/private/manager.go
index 10f80756be7..28c2debe77c 100644
--- a/routers/private/manager.go
+++ b/routers/private/manager.go
@@ -5,6 +5,7 @@ package private
 
 import (
 	"net/http"
+	"time"
 
 	"gitea.dev/models/db"
 	"gitea.dev/modules/graceful"
@@ -34,7 +35,7 @@ func FlushQueues(ctx *context.PrivateContext) {
 		// Save the hammer ctx here - as a new one is created each time you call this.
 		baseCtx := graceful.GetManager().HammerContext()
 		go func() {
-			err := queue.GetManager().FlushAll(baseCtx, opts.Timeout)
+			err := queue.GetManager().FlushAll(baseCtx, time.Duration(opts.Timeout))
 			if err != nil {
 				log.Error("Flushing request timed-out with error: %v", err)
 			}
@@ -44,7 +45,7 @@ func FlushQueues(ctx *context.PrivateContext) {
 		})
 		return
 	}
-	err := queue.GetManager().FlushAll(ctx, opts.Timeout)
+	err := queue.GetManager().FlushAll(ctx, time.Duration(opts.Timeout))
 	if err != nil {
 		ctx.PrivateUserErrorf(http.StatusRequestTimeout, "%v", err)
 		return