thank you again!
For a quick tryout I just puttet the following in the .mailfilter, right at the end of the file:
if ("$HOST" == "testdomain.de")
`/bin/echo $RECIPIENT >> /tmp/ticker.txt`
The file /tmp/ticker.txt exist and is 777, owner is root.
Nothing happens (also, if I try to echo a string like test).
But maybe I misunderstood something ....
Shall this has to work for an incoming mail for email@example.com
Of course, testdomain exists and all the textmails are well transported to the ispconfig-mailstore.