Idiot needs help please

[Stupinder]

I'm using YPOP with Yahoo but get a 0x80042109 error when i try to send a test -i've followed the install etc to the letter. I'm convinced this is a problem with the Ports, currently 110 and 25 . I've read the sticky and downloaded the bit of software that tells you what is using these ports but its all a bit beyond me.
What ports do i need to change YPO and Outlook to - I tries 120 and 26 but the CPU usage went up to 100% which looking at another thread suggested this was because something else was using them.
I'm a complet lightweight when it comes to computers and would really appreciate someones help in plain language please.
Thanyou in advance.
S