Xapian is a generic full-text search library. It doesn’t need anything but text, it certainly doesn’t need Dovecot. But, you seem to be talking about a specific packaging of Xapian for mail (fts-xapian
, which I have no familiarity with). There are many implementations of search that work with Dovecot, and there are multiple ways to trigger indexing. But, yeah, I guess the LMTP thing is about triggering indexing.
You’ll need to do some reading. But, if you’re already filtering spam via another mechanism, you’re most of the way to removing dependence on procmail
. Maybe you want to keep going and removing it completely and switching to Dovecot for delivery. If you’re using Roundcube instead of Usermin, your users already don’t have us handling forwarding and auto-replies (though Virtualmin can manage them in the UI, too). But, if you do that, we’re not the best people to help you with problems. Everyone here is using procmail
.
But, Dovecot does not need to be the delivery agent for full-text search (indexing can happen on searches or via other triggers). If fts-xapian
requires it, that is their business, there are several ways to use the Dovecot fts feature without using LMTP to trigger indexing. So, I think somebody is mixing up how things work. Just don’t use LMTP to trigger indexing, and you should be fine with whatever full-text search you want to use.
It’s somewhat likely we’ll refactor mail at some point to use Dovecot with Sieve for processing rather than procmail
, and we’d probably also look at improving search performance. But, that’s a pretty big undertaking with a lot of code, documentation, and UI work to be done to make it replace the current implementation, so I’m hesitant to commit to any schedule for that (recall we all work part time on this, mostly volunteering). Maybe it’ll be in Virtualmin 8, maybe not. Of course, it’s Open Source, and we welcome contributions. But, this one is a big undertaking, probably not something someone can drop in and implement as a one-off project. It would likely take us months, I assume it’d take someone new to Virtualmin development longer.
That seems like a limitation of Roundcube. You can search inside email without any additional third party search tools using Dovecot. I’m not saying it’s fast (it’s not), but an IMAP client can use the SEARCH command to search within email. If Roundcube is incapable of doing a SEARCH (I don’t know that, I’d be surprised if it is so) via IMAP, then making full-text search work in Dovecot won’t make it work for your Roundcube users. Usermin can do full text search, both with local Maildir access and via IMAP.