I have a very weird issue my customers are getting a lot of sending rejected emails and my server is a Windows 2008 dedicated with Rackspace Managed Hosting. I've been working with them and customers to try and figure out why this is happening but it appears when a customer sends email out from Outlook that email is tagged by there local ISP which in this case is comcast then it comes to my server and is take with a rackspace IP and from there sent out to the recipient server where it is rejected and sent back.
I've checked my server IP's and none of them are on a blacklist. They have a good reputation however the comcast ip has a poor reputation and we are starting to wonder that maybe the comcast ip the mail was tag with might be causing the rejection.
I am currently running Smartermail 9.x and wanted to know is it possible to have Smartermail hide or remove that comcast IP and use the mail server IP since its clean. If my version doesn't is that feature available in the newer version?
I had customer who sent an email out from outlook that was rejected go on to webmail and send a test from there. That email went through with no problems.
This is an emergency that has been going on since Friday. Any information you could help with would be greatly appreciated.