This thread discusses the Content article: PostFix Install for CentOS-4 (WBEL-4 / TaoLinux-4 / RHEL-4) Part 3

My ISP just started blocking Port 25 outgoing a couple of days ago so I can no longer send email via localhost.

I changed my email clients to use the specific smtp server of my ISP (whether it was iSP or my own meails) and separately enter the user name and password to get those emails through.

In squirrelmail setup I changed to smtp and entered the correct details but I don't know where to enter the ISP's required myISPusername and pawword to authenticate.

Does anyone know what I can do?