has this problem just started to happen?
do you have a firewall? if so configure it to allow internet access for both mailwasher and outlook or outlook express etc. there should be a program control menu somewhere in your firewall software to allow you to set up which programs have access or not and its usually very straight forward to do this. you shouldnt have to open and close ports manually.
have you entered the correct pop and smtp server settings, user name and password in outlook and mailwasher account properties?