acl_smtp_rcpt = accept
qualify_domain = test.ex
-errors_copy = *@* ${quote_local_part::abcd+$domain+$local_part}@test.ex
+errors_copy = *@* ${quote_local_part::abcd+$domain+\
+ ${if eq{$local_part}{CALLER}{xxxx}{$local_part}}}@test.ex
trusted_users = CALLER