SendGrid + Temboo

DropBox.php

$session = new Temboo_Session('ACCOUNT_NAME', 'APP_KEY_NAME', 'APP_KEY_VALUE');
$listFolderContents = new Dropbox_ListFolderContents($session); 
$inputs = $listFolderContents->newInputs(array('ResponseFormat' => 'json')); 
$inputs->setCredential('Dropbox'); 

$results = $listFolderContents->execute($inputs)->getResults();

SendGrid.php

$session = new Temboo_Session('ACCOUNT_NAME', 'APP_KEY_NAME', 'APP_KEY_VALUE');
$sendMail = new SendGrid_WebAPI_Mail_SendMail($session); 
$inputs->setCredential('Sendgrid'); 
$inputs->setSubject('Hello World!')
       ->setHTML('This is my email')
       ->setTo("[email protected]")
       ->setFrom("[email protected]");

$results = $sendMail->execute($inputs)->getResults();