Ok, I have gone over the forums here and noticed a couple of posts on changing the sendmail configuration to allow port 587. Since most ISP's block port 25, and port 587 is a secondary standard, I am looking to implement the change. Since the post regarding the change is 2-years old, I am seeking the proper way to make the change. I have tried to edit the sendmail.mc file and enabled the line: DAEMON_OPTIONS('Port=submission, Name=MSA, M=Ea')dnl then restarted sendmail, I get a password prompt from Outlook when trying to send email. Before it would only attempt them come back with an error stating it couldn't send. I tried a few different settings within Outlook to no avail. I also did a send from another account I have via earthlink to my mail server, and it was rejected as port 25 was no longer open. I went back in, dnl'd the line back out, restarted sendmail, did a test and was back to square one (email from outside sources accepted, but cannot send due to port 25 block by Cox). What I need to do is enable port 587 so that any client can send through it, and I would also like to enable port 3535 as an alternate config for some clients. What is the proper way to edit sendmail.mc to allow this? I know on my prior config, which was done through sendmail.cf directly, whenever the server was rebooted the settings were lost. I need to always ensure 25, 587 and 3535 are always open for my clients, regardless if the system is rebooted. One thing I did notice, maybe this is ProX specific, is that the "only listen on IPv4 loopback (127.0.0.1)" is enabled by default! Now I was thinking this had to do with mailscanner to prevent circumventing things, but I am not sure. Want to make sure mailscanner is doing it's job, and still accepting emails from listed ports.