title: Magento:exception 'Zend_Mail_Transport_Exception' with message 'Unable to send mail
body: <h2> Magento 1.7, Qmail as smtp, Parallel plesk 10.3, Centos</h2>
  
  <p>Since a few days one of my magento installation is not sending email, the problem affect only one magento installation.</p>
  
  <p>the excepTion log report:</p>
  
  <pre><code>2013-10-14T15:05:41+00:00 ERR (3):
  exception 'Zend_Mail_Transport_Exception' with message 'Unable to send mail. ' in /var/www/vhosts/domain.ext/httpdocs/lib/Zend/Mail/Transport/Sendmail.php:137
   Stack trace:
  #0 /var/www/vhosts/domain.ext/httpdocs/lib/Zend/Mail/Transport/Abstract.php(348): Zend_Mail_Transport_Sendmail-&gt;_sendMail()
  #1 /var/www/vhosts/domain.ext/httpdocs/lib/Zend/Mail.php(1194): Zend_Mail_Transport_Abstract-&gt;send(Object(Zend_Mail))
   #2 /var/www/vhosts/domain.ext/httpdocs/app/code/core/Mage/Core/Model/Email/Template.php(454): Zend_Mail-&gt;send()
  #3 /var/www/vhosts/domain.ext/httpdocs/app/code/core/Mage/Core/Model/Email/Template.php(506): Mage_Core_Model_Email_Template-&gt;send(Array, Array, Array)
  #4 /var/www/vhosts/domain.ext/httpdocs/app/code/core/Mage/Core/Model/Email/Template/Mailer.php(79): Mage_Core_Model_Email_Template-&gt;sendTransactional('sales_email_ord...', 'sales', Array, Array, Array, '5')
   #5 /var/www/vhosts/domain.ext/httpdocs/app/code/core/Mage/Sales/Model/Order.php(1393): Mage_Core_Model_Email_Template_Mailer-&gt;send()
   #6 /var/www/vhosts/domain.ext/httpdocs/app/code/core/Mage/Adminhtml/controllers/Sales/OrderController.php(276): Mage_Sales_Model_Order-&gt;sendOrderUpdateEmail('1', 'test')
   #7 /var/www/vhosts//domain.ext/httpdocs/app/code/core/Mage/Core/Controller/Varien/Action.php(419): Mage_Adminhtml_Sales_OrderController-&gt;addCommentAction()
   #8 /var/www/vhosts//domain.ext/httpdocs/app/code/core/Mage/Core/Controller/Varien/Router/Standard.php(250): Mage_Core_Controller_Varien_Action-&gt;dispatch('addComment')
   #9 /var/www/vhosts/domain.ext/httpdocs/app/code/core/Mage/Core/Controller/Varien/Front.php(176): Mage_Core_Controller_Varien_Router_Standard-&gt;match(Object(Mage_Core_Controller_Request_Http))
   #10 /var/www/vhosts/domain.ext/httpdocs/app/code/core/Mage/Core/Model/App.php(354): Mage_Core_Controller_Varien_Front-&gt;dispatch()
   #11 /var/www/vhosts/domain.ext/httpdocs/app/Mage.php(683): Mage_Core_Model_App-&gt;run(Array)
  #12 /var/www/vhosts/domain.ext/httpdocs/index.php(87): Mage::run('', 'store')
  #13 {main}
  </code></pre>
  
  <hr>
  
  <p>the qmail wrapper show the email header with no problems
  no errors in mail.log</p>
  
  <p>error.log reports: </p>
  
  <pre><code> qmail-inject: fatal: unable to parse this line:
   From: Global-seller: e-commerce &lt;senderemail&gt; 
  </code></pre>
  
  <p><strong>* (senderemail = right magento email) *</strong></p>
  
  <p>the smtp on server is running fine (all other domains are sending e-mails)
  Other magento installed on same server with different domain have no problems.
  The magento setting are well configured as localhost on port 25</p>
  
  <h2>postfix is not installed on the server</h2>
  
  <p>Any tips?
  thanks</p>