Hey everyone, wanted to see if I could get some help on this. I have a CentOS VPS running Virtualmin and Postfix for my email server. I am having issues with emails being filtered my gmail on the recipients end. Now here's the interesting part- if I send from my iPhone or from Roundcube webmail it works fine, hits their inbox, and doesnt get filtered. If I send from Outlook on either of my desktops, it gets filtered everytime... Thoughts?
I think this might relate somewhere down the line to the difference in IP addresses when sending locally from your server or remotly from Outlook (Although the iphone part throws a spanner in that). Ive seen issues on my servers before where mail is sent to spam because the domain the email was being sent from has a different IP than the mail sender. This can also happen if your servers hostname is myhostname.com but your sending email from mydomain.com. Personally I would start by inspecting the headers on email sent from Roundcube and Outlook for differences or clues that might point you in a better direction.