I have been trying CiviMail to send emails with CiviCRM 4.6.9. and drupal 7. When I send mails using the mail system not many of them reach the destination mailbox. They are marked as delivered by the mail reports, but only a few are marked as opened. When I check with the individual users they are not getting my emails, I am also not receiving bounces. I have checked and our domain has not been blacklisted. If I send emails from my own email program they generally all get through.
Any suggestions as to why my emails are not getting through when sent from Civimail?