i use sendmail for my kmail client.
the problem is that some domains do not accept mails composed using the kmail
client.

i had a look at the mail headers and found that
Return-Path: <root@...>

so the mail server at the other end sees this as a bad domain and rejects my
mail.

believe it can be changed by editing the sendmail.cf file.
but i dont know where and what changes are to be made ?

can anybody please help ?