What I am wondering is if there is an IMAP server available that supports the IMAP SEARCH command (https://www.rfc-editor.org/rfc/rfc1730#section-6.4.4), and is fast.
I have had a look around at ways that this can be done, including using DBMail to store all of the incoming emails, but to be honest so far what I have found is that most of the IMAP solutions have some sort of downfall – none really seem to be aimed specifically at what I want to do.
For example, DBMail is almost perfect, however it stores attachments in the database. What I would love to have is that inside the database all of the messages (HTML, TXT) are stored, but the attachments are stored somewhere else on the filesystem.
Best Answer
Dovecot should : http://wiki2.dovecot.org/Plugins/FTS/Solr I never test solr on it.