[fetchmail] problem when local user is in the mailing list

Hello

First of all let me describe what i have:
  1) Linux RedHat 8.0
  2) Fetchmail 6.2.0
  3) Sendmail
  4) procmail
  5) multidrop mail account for my.domain.com at my ISP - my.isp.com

Sequence of mail receiving:
  fetchmail -> sendmail -> procmail -> local user

My /root/.fetchmailrc configuration (So, fethchmail is run as root ;)) :
  set postmaster root
  set syslog
  poll my.isp.com
  protocol pop3
  localdomains my.domain.com
  username MyUserName
  password MyPassWord
  to *(_at_)my(_dot_)domain(_dot_)com is *(_at_)localhost here
  
Problem:
  when local user is in the mailing list all mails from that mailing
  list is directed to postmaster on my Linux

Solution:
  I don't know ... maybe you do ?....

P.S. if it is solvable at all, it would be nice to be solved either on
fetchmail level or sendmail level (even using rewriting rules)...