I've contacted CM support and although they have seen this issue once before they can't recall the exact cause/fix so i'm asking the community!
When a campaign is sent out - I and people in our organisation - are receiving the emails, however when I send out a test preview email, using the same 'From' address, I don't receive the test preview email. No one in our organisation can receive a test preview email from CM.
CM support suggested it moght have something to do with the Return-Path header value in the test preview email. Has anyone else had this problem, any suggestions on what I can do to fix it? I'm not an IT person so I need to be able to suggest a fix to our IT dept who don't have any suggestions other than to change service.
This is actually fairly common, where your server is rejecting email sent with a from address of the same domain it controls (but not sent via it). The preview messages and full campaigns different in what the return-path is, so it's not unusual that one may get through and the other might not. There is actually some information about that here. In many cases your mail admins should be able to whitelist our IPs to allow the email to make it through.
Thanks very much Diana, I will ask our it dept to whitelist the CM ip's.