diff --git a/src/Symfony/Component/Mime/CHANGELOG.md b/src/Symfony/Component/Mime/CHANGELOG.md
index 796cfdd155..0b252bd1d3 100644
--- a/src/Symfony/Component/Mime/CHANGELOG.md
+++ b/src/Symfony/Component/Mime/CHANGELOG.md
@@ -1,6 +1,11 @@
 CHANGELOG
 =========
 
+4.4.0
+-----
+
+ * Added `AbstractPart::asDebugString()`
+
 4.3.3
 -----
 
diff --git a/src/Symfony/Component/Mime/Part/AbstractMultipartPart.php b/src/Symfony/Component/Mime/Part/AbstractMultipartPart.php
index 76f58128c1..48b8620232 100644
--- a/src/Symfony/Component/Mime/Part/AbstractMultipartPart.php
+++ b/src/Symfony/Component/Mime/Part/AbstractMultipartPart.php
@@ -74,6 +74,20 @@ abstract class AbstractMultipartPart extends AbstractPart
         yield '--'.$this->getBoundary()."--\r\n";
     }
 
+    public function asDebugString(): string
+    {
+        $str = parent::asDebugString();
+        foreach ($this->getParts() as $part) {
+            $lines = explode("\n", $part->asDebugString());
+            $str .= "\n  └ ".array_shift($lines);
+            foreach ($lines as $line) {
+                $str .= "\n  |".$line;
+            }
+        }
+
+        return $str;
+    }
+
     private function getBoundary(): string
     {
         if (null === $this->boundary) {
diff --git a/src/Symfony/Component/Mime/Part/AbstractPart.php b/src/Symfony/Component/Mime/Part/AbstractPart.php
index c9df1050a3..93892d9df6 100644
--- a/src/Symfony/Component/Mime/Part/AbstractPart.php
+++ b/src/Symfony/Component/Mime/Part/AbstractPart.php
@@ -50,6 +50,11 @@ abstract class AbstractPart
         yield from $this->bodyToIterable();
     }
 
+    public function asDebugString(): string
+    {
+        return $this->getMediaType().'/'.$this->getMediaSubtype();
+    }
+
     abstract public function bodyToString(): string;
 
     abstract public function bodyToIterable(): iterable;
diff --git a/src/Symfony/Component/Mime/Part/DataPart.php b/src/Symfony/Component/Mime/Part/DataPart.php
index e8436712ca..128c53eb62 100644
--- a/src/Symfony/Component/Mime/Part/DataPart.php
+++ b/src/Symfony/Component/Mime/Part/DataPart.php
@@ -103,6 +103,16 @@ class DataPart extends TextPart
         return $headers;
     }
 
+    public function asDebugString(): string
+    {
+        $str = parent::asDebugString();
+        if (null !== $this->filename) {
+            $str .= ' filename: '.$this->filename;
+        }
+
+        return $str;
+    }
+
     private function generateContentId(): string
     {
         return bin2hex(random_bytes(16)).'@symfony';
diff --git a/src/Symfony/Component/Mime/Part/TextPart.php b/src/Symfony/Component/Mime/Part/TextPart.php
index 10aa94f154..77ab980219 100644
--- a/src/Symfony/Component/Mime/Part/TextPart.php
+++ b/src/Symfony/Component/Mime/Part/TextPart.php
@@ -144,6 +144,19 @@ class TextPart extends AbstractPart
         return $headers;
     }
 
+    public function asDebugString(): string
+    {
+        $str = parent::asDebugString();
+        if (null !== $this->charset) {
+            $str .= ' charset: '.$this->charset;
+        }
+        if (null !== $this->disposition) {
+            $str .= ' disposition: '.$this->disposition;
+        }
+
+        return $str;
+    }
+
     private function getEncoder(): ContentEncoderInterface
     {
         if ('8bit' === $this->encoding) {