1 files changed, 11 insertions, 7 deletions

diff --git a/lib/sendgrid.js b/lib/sendgrid.js
index c7fc0b7..12c8b85 100644
--- a/lib/sendgrid.js
+++ b/lib/sendgrid.js
@@ -27,9 +27,11 @@ function SendGrid(api_user, api_key) {
  * @param  {Email|Object}  email     An email object or a hash that has
  *                                   the values for the email to be sent.
  * @param  {Function}      callback  A function to call when the processing is done.
+ *                                   This parameter is optional.
  */
 SendGrid.prototype.send = function(email, callback) {
-  var self = this;
+  var self = this
+    , cb = callback || function() { };
 
   var boundary = Math.random();
 
@@ -71,7 +73,7 @@ SendGrid.prototype.send = function(email, callback) {
       });
       res.on('end', function() {
         var json = JSON.parse(content);
-        callback(json.message == 'success', json.errors);
+        cb(json.message == 'success', json.errors);
       });
     });
 
@@ -93,7 +95,7 @@ SendGrid.prototype.send = function(email, callback) {
       if (success) {
         send_rest();
       } else {
-        callback(false, message);
+        cb(false, message);
       }
     });
   } else {
@@ -108,10 +110,12 @@ SendGrid.prototype.send = function(email, callback) {
  * @param    {Email|Object}  email     An email object or a hash that has
  *                                     the values for the email to be sent.
  * @param    {Function}      callback  A function to call when the processing is done.
+ *                                     This parameter is optional.
  */
 SendGrid.prototype.smtp = function(email, callback) {
   var self = this
-    , smtpTransport;
+    , smtpTransport
+    , cb = callback || function() { };
 
   // SMTP settings
   smtpTransport = nodemailer.createTransport("SMTP", {
@@ -126,9 +130,9 @@ SendGrid.prototype.smtp = function(email, callback) {
     smtpTransport.sendMail(email.toSmtpFormat(), function(error, response) {
       smtpTransport.close();
       if(error) {
-        return callback(false, response);
+        return cb(false, response);
       }
-      return callback(true, response);
+      return cb(true, response);
     });
   }
 
@@ -141,7 +145,7 @@ SendGrid.prototype.smtp = function(email, callback) {
       if (success) {
         send_smtp();
       } else {
-        callback(false, message);
+        cb(false, message);
       }
     });
   } else {