PHPMailer仅添加单个PDF附件问题求助

Hey there! Let's figure out why only one of your PDF attachments is being added successfully with PHPMailer. Below are the most common checks and fixes to resolve this:

• Verify file existence and correct paths
  It's easy to misspell a filename or mess up a path—double-check that both files actually exist at the specified locations. You can add quick validation code to confirm:

  $file1 = $_SERVER["DOCUMENT_ROOT"] . '/wp-content/plugins/xyz-user-registration/images/iraq_visa_form_test.pdf';
  $file2 = $_SERVER["DOCUMENT_ROOT"] . '/wp-content/plugins/xyz-user-registration/images/iraq_visa_form.pdf';
  
  // Check if files exist
  if (!file_exists($file1)) {
      error_log("Missing file: " . $file1);
      echo "File 1 not found!";
  }
  if (!file_exists($file2)) {
      error_log("Missing file: " . $file2);
      echo "File 2 not found!";
  }
  

  Also, watch out for case sensitivity—on Linux servers, Iraq_Visa_Form.pdf is not the same as iraq_visa_form.pdf.

• Check file permissions
  Make sure the PHP process has permission to read both files. Typically, files should have permissions set to 644 and folders to 755. If the web server can't access a file, PHPMailer won’t be able to attach it.

• Enable PHPMailer debugging
  Turn on debug mode to see exactly what’s happening when adding attachments—this will reveal any hidden errors:

  $mail->SMTPDebug = 2; // Enable detailed debug output (disable in production)
  $mail->Debugoutput = 'html'; // Format debug output for readability
  

  Look for messages like "Failed to read file" or permission-related errors.

• Confirm attachment addition success
  Each addAttachment() call returns a boolean indicating success. Check these values to see which step is failing:

  $success1 = $mail->addAttachment($attachedfile, 'Visa Application');
  $success2 = $mail->addAttachment($attachedfile2, 'Visa Application 2');
  
  var_dump($success1, $success2); // Should output bool(true) for both if working
  

• Specify file extensions explicitly
  Sometimes mail clients struggle to recognize attachments without proper extensions. Try adding .pdf to your attachment names:

  $mail->addAttachment($attachedfile, 'Visa Application.pdf'); 
  $mail->addAttachment($attachedfile2, 'Visa Application 2.pdf');
  

• Check for code interruptions
  Make sure there’s no code after the first addAttachment() that resets the $mail object, throws an uncaught exception, or exits early—this would stop the second attachment from being added.

Start with the file existence check—it’s the most common culprit here! Once you confirm both files are accessible, the rest of the steps should help narrow down any remaining issues.

内容的提问来源于stack exchange，提问作者Ali