If you are talking about the yahoo pop question, yes you need pop enabled to use pop yahoo email. However if you use BIS through Tmobile for example, you can get away with that for no charge and also have email reconsiliation as well as the ability to spoof your return email address.
ie: my gmail account is the only account I give out, but I have it forward to my yahoo account, but when I reply from my device it will show my gmail as the return addy and also give me the same option in yahoo.
hope that helps