[Exim] Mail and Freeze in system filter

Hello

Probably I missed something because there is a strange problem.
When I use "mail" before "freeze" in very simple system filter, the message
originated from "mail" command do not send
At the same time if I use "finish" instead "freeze" the message is sent
correctly.

The system filter looks like:
if ($message_body contains "..." and not error_message and first_delivery
then
mail to user@domain subject "..." text "text here"
#freeze
seen finish
endif

I guess an option "message_filter_reply_transport" caused the problem but I'm
not sure. In any case I've set message_filter_reply_transport=address_reply
and think it's correct.

Any advice ?
--
Dimitry