Are there any good articles about how to configure your XenForo host to send emails reliably (so they are not treated as SPAM)? Ideally, I'd like the emails that go our for verification of new registrations to come from email@example.com - but that is a Google Apps account. Another alternative we've been looking at is using SendGrid. But, I'm not sure what is the best way to hook up the Zend Framework mail transport that XenForo uses with either Google Apps or with SendGrid. We are running XenForo on Ubuntu 13.04 on an Amazon EC2 instance.