I'm relatively new to transactional email providers and started using Mandrill for this forum and so far been excellent for email delivery and providing usefull mail delivery statistics in Mandrillapp interface. However, I came across this brief review comparison of different transactional email providers done by a web host and has some juicy information for comparing Mandrill vs SendGrid vs Amazon SES vs Mailgun vs Postmark. https://www.webhostingtalk.com/showthread.php?t=1417122 As I use Mandrill, I'm concerned about the reported problems where Mandrill would mark an email as delivered but it actually hasn't been delivered. The same web host posted a separate thread at https://www.webhostingtalk.com/showthread.php?t=1408109. Thought it would be a good read for users here who are using Mandrill so they can double check if their emails are really being delivered as stated. Also anyone have experience with the other mentioned transactional email providers above ?