I recently changed hosts. I did a backup and restore with mailcow. For whatever reason, solr wasn’t coming back with any results in SOGo even though there were many files in the solr index. I stopped the solr container (# docker ps, and then # docker stop whatever), removed the docker volume (# docker rm whatever or maybe it was # docker volume rm whatever, bye-bye solr index), and then did a # docker-compose up -d The solr container came back up OK. It looks like now solr is properly indexing and returning results in SOGo. Of course, it’s only indexing new mail that comes in. That makes sense and isn’t really a problem since I just recently started using mailcow as my primary mail. I’m a noob to docker, so thought I would share in case it helps another noob.