you appear to be referring to the iTools account, and that is the port to which you connect, not the port from which you connect. The port to which you connect can not be changed, or you won't connect at all. If you make a pop account, you appear to be able to enter the port if you so desire.
I'm not sure if this helped, but if you did not get your answer from this reply, I suggest you expand on your problem.
Thanks for letting me a answer a question.