Help on smtp and rcpthosts !!

[Xionghui Chen]

This is real urgent:

every time when I send mail via port 25, if the domain of the mail address is not 
belong in the file control/rcpthosts, it says:
553 sorry, that domain isn't in my list of allowed rcpthosts (#5.7.1)

do this mean that I have to put all my possible rcpt domains in the rcpthots file? 
i.e, i have to put yahoo.com in rcpthosts, or else I cannot send mail to 
[EMAIL PROTECTED]

help me out, please!