[exim] Transport filter process failed

Hi,

I am testing exim 4.89 update in my environment (CentOS release 6.9).
I got following error:
transport filter process failed (127): unable to execute command

My original transport_filter replaced with this simple filter but even it
fall...
remote_smtp_test:
driver = smtp
size_addition = 4096
delay_after_cutoff = false
hosts_try_chunking =
transport_filter = /bin/cat

When i send the same test message with swaks in debug mode then exim
deliver message as expected.
Both debug commands deliver message:
exim -bd -d+all
exim -d -M 1dcEwb-0002CQ-JC

Can someone help me understand why transport filter works only with '-d'
argument?

Thanks.
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