Conny wrote (2022-02-03):

 CE> It seems like binkd create some 2.203.0.0.bsy, 2.2.2.0.bsy, 2.20.0.0.bsy
 CE> and 2.203.0.0.csy files and at the end removing them.

binkd creates .bsy files for every AKA of the remote system and deletes them when the call has finished. This is not related to your problem.

 CE> The line: removing flo: /home/conny/amigahd/MAI/Outbound/2.203.0.0.dlo
 CE> Is also strange?

Also normal behavior if run binkd with the -P parameter.

The first thing to debug this problem is to make sure that binkd is not running in the background. Do you still have the binkd package from Ubuntu installed. Usually Debian/Ubuntu enables and starts services in installation (I don't remember if this is the case with binkd). If the package is still installed, do stop it with:

sudo systemctl stop binkd

and optionally disable it:

sudo systemctl disable binkd

Then toss some outgoing mail with TrapToss. It should create some FLO/DLO/CLO/HLO file.

You could also try

grep -A4 start_file_transfer /srv/log/binkd.log

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