[bks]

Brad from DuoCircle here, if you need any help with sending let me know we have a few services that can help. We can smarthost your SMTP traffic on the outbound or we can forward your inbound email to the right destination.

My $.02 on the conversation is to double check your IP on some of the RBL services http://www.anti-abuse.org/multi-rbl-check/ to check to see if you are listed for any reason.

And then send a test email to https://www.mail-tester.com/ and check their scores. You SHOULD be able to get a 10/10 with a blank email as long as your authentication aligns.

Feel free to email me and I would be happy to help.