I tried to search a mailbox on my mailcow server via IMAP (using C# and MimeKit) for known message-ids - didn´t work at all, all results are empty.
Then I tried to search a mailbox again via IMAP for specific To- or From-domains. The result wasn´t exactly what I expected, e.g. search for s-web.de returned mails with web.de, but at least I think I can rule out that my queries are wrong.
Is this behaviour expected? Is there a configuration on what headers SOLR is indexing?
So far I was using the old SOLR search, but I am willing to switch to the new Flatcurve FTS Engine search if that behaves more as expected.