magento not sending out any mails, how to debug?

Question

Magento is not sending out any emails, transnational, contact form gives error

 cannot send your mail at this moment

I checked

• Mail setup in magento, all email accounts are set in settings
• php mail works fine a test.php with php mail sends out a message
• checked my mailserver logs but see nothing there no errors

• /var/log/system.log and exception.log shows only an error not the cause of the error

  exception 'Zend_Mail_Transport_Exception' with message 'Unable to send mail. ' in /var/webshop/httpdocs/lib/Zend/Mail/Transport/Sendmail.php:137

Answer 1

I ran into this problem when Magento was not sending out forgot password emails (yet reporting it did to the user) then after looking in /var/log/exception.log found the error it was generating was:

2012-05-30T04:27:54+00:00 ERR (3): 
exception 'Exception' with message 'This letter cannot be sent.' in /home/magento/www/app/code/core/Mage/Core/Model/Email/Template.php:354
Stack trace:
#0 /home/magento/www/app/code/core/Mage/Core/Model/Email/Template.php(463): Mage_Core_Model_Email_Template->send(Array, Array, Array)
#1 /home/magento/www/app/code/core/Mage/Core/Model/Email/Template/Mailer.php(79): Mage_Core_Model_Email_Template->sendTransactional('customer_passwo...', 'support', Array, Array, Array, '1')
#2 /home/magento/www/app/code/core/Mage/Customer/Model/Customer.php(646): Mage_Core_Model_Email_Template_Mailer->send()
#3 /home/magento/www/app/code/core/Mage/Customer/Model/Customer.php(663): Mage_Customer_Model_Customer->_sendEmailTemplate('customer/passwo...', 'customer/passwo...', Array, '1')
#4 /home/magento/www/app/code/core/Mage/Customer/controllers/AccountController.php(554): Mage_Customer_Model_Customer->sendPasswordResetConfirmationEmail()
#5 /home/magento/www/app/code/core/Mage/Core/Controller/Varien/Action.php(420): Mage_Customer_AccountController->forgotPasswordPostAction()
#6 /home/magento/www/app/code/core/Mage/Core/Controller/Varien/Router/Standard.php(250): Mage_Core_Controller_Varien_Action->dispatch('forgotpasswordp...')
#7 /home/magento/www/app/code/core/Mage/Core/Controller/Varien/Front.php(176): Mage_Core_Controller_Varien_Router_Standard->match(Object(Mage_Core_Controller_Request_Http))
#8 /home/magento/www/app/code/core/Mage/Core/Model/App.php(349): Mage_Core_Controller_Varien_Front->dispatch()
#9 /home/magento/www/app/Mage.php(640): Mage_Core_Model_App->run(Array)
#10 /home/magento/www/index.php(84): Mage::run('default', 'store')
#11 {main}

So opened up /app/code/core/Mage/Core/Model/Email/Template.php and found the code that was throwing this error (on line 354) was:

if (!$this->isValidForSend()) {
    Mage::logException(new Exception('This letter cannot be sent.')); // translation is intentionally omitted
    return false;
}

So had a look at isValidForSend():

public function isValidForSend()
{
    return !Mage::getStoreConfigFlag('system/smtp/disable')
        && $this->getSenderName()
        && $this->getSenderEmail()
        && $this->getTemplateSubject();
}

Added some logging of the variables at the start of the function as one of these must be returning false:

Mage::Log(var_export(!Mage::getStoreConfigFlag('system/smtp/disable'),true).';'.var_export($this->getSenderName(),true).';'.var_export($this->getSenderEmail(),true).';'.var_export($this->getTemplateSubject(),true),null,'email.log');

Which creates the log file /var/log/email.log which had:

2012-05-30T04:44:37+00:00 DEBUG (7): false;'CustomerSupport';'[email protected]';'Password Reset Confirmation for {{var customer.name}}'

So the problem was: !Mage::getStoreConfigFlag('system/smtp/disable') which you can fix up in Admin > System > Configuration > Advanced > System > Mail Sending Settings and change Disable Email Communications to No so the emails are NOT disabled.

Now it works :)