Created a new method to return the transport class before send. In some cases you need to do extra calls/configurations before send.

lib/Cake/Network/CakeEmail.php

@@ -193,6 +193,13 @@ class CakeEmail {
  */
 	protected $_transportName = 'mail';
 
+/**
+ * Instance of tranport class
+ *
+ * @var object
+ */
+	protected $_transportClass = null;
+
 /**
  * charset the email is sent in
  *
@@ -671,9 +678,32 @@ class CakeEmail {
 			return $this->_transportName;
 		}
 		$this->_transportName = (string)$name;
+		$this->_transportClass = null;
 		return $this;
 	}
 
+/**
+ * Return the transport class
+ *
+ * @return object
+ * @thrown SocketException
+ */
+	public function transportClass() {
+		if ($this->_transportClass) {
+			return $this->_transportClass;
+		}
+		list($plugin, $transportClassname) = pluginSplit($this->_transportName, true);
+		$transportClassname .= 'Transport';
+		App::uses($transportClassname, $plugin . 'Network/Email');
+		if (!class_exists($transportClassname)) {
+			throw new SocketException(__d('cake', 'Class "%s" not found.', $transportClassname));
+		} elseif (!method_exists($transportClassname, 'send')) {
+			throw new SocketException(__d('cake', 'The "%s" do not have send method.', $transportClassname));
+		}
+
+		return $this->_transportClass = new $transportClassname();
+	}
+
 /**
  * Message-ID
  *
@@ -755,11 +785,17 @@ class CakeEmail {
 		if (empty($config)) {
 			return $this->_config;
 		}
+
 		if (is_array($config)) {
 			$this->_config = $config;
 		} else {
 			$this->_config = (string)$config;
 		}
+
+		if ($this->_transportClass) {
+			$this->_transportClass->config($this->_config);
+		}
+
 		return $this;
 	}
 
@@ -828,16 +864,9 @@ class CakeEmail {
 			$this->_message[] = '';
 		}
 
-		list($plugin, $transportClassname) = pluginSplit($this->_transportName, true);
-		$transportClassname .= 'Transport';
-		App::uses($transportClassname, $plugin . 'Network/Email');
-		if (!class_exists($transportClassname)) {
-			throw new SocketException(__d('cake', 'Class "%s" not found.', $transportClassname));
-		} elseif (!method_exists($transportClassname, 'send')) {
-			throw new SocketException(__d('cake', 'The "%s" do not have send method.', $transportClassname));
-		}
+		$transport = $this->transportClass();
+		$transport->config($config);
 
-		$transport = new $transportClassname($config);
 		return $transport->send($this);
 	}
 
@@ -865,6 +894,7 @@ class CakeEmail {
 		$this->_message = '';
 		$this->_emailFormat = 'text';
 		$this->_transportName = 'mail';
+		$this->_transportClass = null;
 		$this->_attachments = array();
 		$this->_config = 'default';
 		return $this;

lib/Cake/Network/Email/AbstractTransport.php

@@ -31,16 +31,6 @@ abstract class AbstractTransport {
  */
 	protected $_config = array();
 
-/**
- * Constructor
- *
- */
-	public function __construct($config = array()) {
-		if (!empty($config)) {
-			$this->_config = $config;
-		}
-	}
-
 /**
  * Send mail
  *
@@ -49,6 +39,18 @@ abstract class AbstractTransport {
  */
 	abstract public function send(CakeEmail $email);
 
+/**
+ * Set the config
+ *
+ * @param array $config
+ * @return object $this
+ */
+	public function config($config = array()) {
+		if (!empty($config)) {
+			$this->_config = $config;
+		}
+	}
+
 /**
  * Help to convert headers in string
  *

lib/Cake/Network/Email/SmtpTransport.php

@@ -47,16 +47,6 @@ class SmtpTransport extends AbstractTransport {
  * @thrown SocketException
  */
 	public function send(CakeEmail $email) {
-		$config = array(
-			'host' => 'localhost',
-			'port' => 25,
-			'timeout' => 30,
-			'username' => null,
-			'password' => null,
-			'client' => null
-		);
-		$this->_config += $config;
-
 		$this->_cakeEmail = $email;
 
 		$this->_connect();
@@ -68,6 +58,24 @@ class SmtpTransport extends AbstractTransport {
 		return true;
 	}
 
+/**
+ * Set the configuration
+ *
+ * @param array $config
+ * @return object $this
+ */
+	public function config($config = array()) {
+		$default = array(
+			'host' => 'localhost',
+			'port' => 25,
+			'timeout' => 30,
+			'username' => null,
+			'password' => null,
+			'client' => null
+		);
+		$this->_config = $config + $default;
+	}
+
 /**
  * Connect to SMTP Server
  *