Just to clarify, our clients are able to pop their accounts off of our server using port 25. They just configure outlook in the usual way, and everything pops (or imaps) just fine. The problem occurs when they attempt to send email from our server, using the connection from their ISP...
Only change the items specified -you should not need to change POP3 / IMAP settings. These instructions are only for Mac Mail on Yosemite 10.10 - for other email programs please seeHow To Setup AuthSMTPorcontactus. We have instructions for bothdefault SMTP portandalternate SMTP portconfigurations...