solr does not index files in the mailbox

[Andreas Meyer]

Hello!

I startet solr and configured dovecot to use it. Dovecot just indexes
two files dovecot.index.log and dovecot.mailbox.log but nothing in
the cur directory.

./post -c myfiles /home/a.meyer/Postfach
java -classpath /home/andreas/solr-5.5.1/dist/solr-core-5.5.1.jar -Dauto=yes -Dc=myfiles -Ddata=files -Drecursive=yes org.apache.solr.util.SimplePostTool /home/a.meyer/Postfach
SimplePostTool version 5.0.0
Posting files to [base] url http://localhost:8983/solr/myfiles/update...
Entering auto mode. File endings considered are xml,json,jsonl,csv,pdf,doc,docx,ppt,pptx,xls,xlsx,odt,odp,ods,ott,otp,ots,rtf,htm,html,txt,log
Entering recursive mode, max depth=999, delay=0s
Indexing directory /home/a.meyer/Postfach (2 files, depth=0)
POSTing file dovecot.index.log (text/plain) to [base]/extract
POSTing file dovecot.mailbox.log (text/plain) to [base]/extract
Indexing directory /home/a.meyer/Postfach/cur (0 files, depth=1)
Indexing directory /home/a.meyer/Postfach/new (0 files, depth=1)
Indexing directory /home/a.meyer/Postfach/tmp (0 files, depth=1)
2 files indexed.
COMMITting Solr index changes to http://localhost:8983/solr/myfiles/update...
Time spent: 0:00:00.751

If I give the cur folder as startingpoint

./post -c myfiles /home/a.meyer/Postfach/cur
java -classpath /home/andreas/solr-5.5.1/dist/solr-core-5.5.1.jar -Dauto=yes -Dc=myfiles -Ddata=files -Drecursive=yes org.apache.solr.util.SimplePostTool /home/a.meyer/Postfach/cur
SimplePostTool version 5.0.0
Posting files to [base] url http://localhost:8983/solr/myfiles/update...
Entering auto mode. File endings considered are xml,json,jsonl,csv,pdf,doc,docx,ppt,pptx,xls,xlsx,odt,odp,ods,ott,otp,ots,rtf,htm,html,txt,log
Entering recursive mode, max depth=999, delay=0s
Indexing directory /home/a.meyer/Postfach/cur (0 files, depth=0)
0 files indexed.
COMMITting Solr index changes to http://localhost:8983/solr/myfiles/update...
Time spent: 0:00:00.102

nothing is indexed although the directory contains 4 mails.

What am I doing wrong?

Greetings

Andreas