Thanks a lot for the help. You are right about the JSON as the default in solr v7.1.0. I now switched it back to XML and now it works. # doveadm -v index -u fail2ban at mydomain.com Inbox doveadm(fail2ban at mydomain.com): Info: INBOX: Caching mails seq=1..388 388/388 Gao On 2017-11-30 02:00 PM, Christian Kivalo wrote: > solr 7 and dovecot