diff --git a/pkg/log/logging.go b/pkg/log/logging.go
index 111bfd029..0b4754189 100644
--- a/pkg/log/logging.go
+++ b/pkg/log/logging.go
@@ -27,6 +27,11 @@ import (
 // logInstance is the instance of the logger which is used under the hood to log
 var logInstance *slog.Logger
 
+// IsInitialized returns true if the logger has been initialized.
+func IsInitialized() bool {
+	return logInstance != nil
+}
+
 // logpath is the path in which log files will be written.
 // This value is a mere fallback for other modules that could but shouldn't be used before calling ConfigureLogger
 var logPath = "."
diff --git a/pkg/mail/domain.go b/pkg/mail/domain.go
index 2bfc58c51..439e0dd7c 100644
--- a/pkg/mail/domain.go
+++ b/pkg/mail/domain.go
@@ -35,9 +35,13 @@ func GetMailDomain() string {
 		}
 	}
 	if hostname, err := os.Hostname(); err == nil && hostname != "" {
-		log.Warningf("Could not determine mail domain from public URL, falling back to hostname %q", hostname)
+		if log.IsInitialized() {
+			log.Warningf("Could not determine mail domain from public URL, falling back to hostname %q", hostname)
+		}
 		return hostname
 	}
-	log.Warningf("Could not determine mail domain from public URL or hostname, falling back to %q", "vikunja")
+	if log.IsInitialized() {
+		log.Warningf("Could not determine mail domain from public URL or hostname, falling back to %q", "vikunja")
+	}
 	return "vikunja"
 }
diff --git a/pkg/models/notifications_test.go b/pkg/models/notifications_test.go
index 526f39951..94c2aca83 100644
--- a/pkg/models/notifications_test.go
+++ b/pkg/models/notifications_test.go
@@ -17,6 +17,7 @@
 package models
 
 import (
+	"os"
 	"testing"
 
 	"code.vikunja.io/api/pkg/config"
@@ -33,7 +34,11 @@ func TestGetThreadID(t *testing.T) {
 	t.Run("default domain when no public URL", func(t *testing.T) {
 		config.ServicePublicURL.Set("")
 		threadID := getThreadID(123)
-		assert.Equal(t, "<task-123@vikunja>", threadID)
+		expectedDomain := "vikunja"
+		if hostname, err := os.Hostname(); err == nil && hostname != "" {
+			expectedDomain = hostname
+		}
+		assert.Equal(t, "<task-123@"+expectedDomain+">", threadID)
 	})
 
 	t.Run("simple domain without port", func(t *testing.T) {
@@ -73,7 +78,11 @@ func TestGetThreadID(t *testing.T) {
 	t.Run("invalid URL falls back to default", func(t *testing.T) {
 		config.ServicePublicURL.Set("not a valid url")
 		threadID := getThreadID(333)
-		assert.Equal(t, "<task-333@vikunja>", threadID)
+		expectedDomain := "vikunja"
+		if hostname, err := os.Hostname(); err == nil && hostname != "" {
+			expectedDomain = hostname
+		}
+		assert.Equal(t, "<task-333@"+expectedDomain+">", threadID)
 	})
 
 	t.Run("URL with path", func(t *testing.T) {