Server-side mail filtering?


NethServer Version: 7.4
Module: mail server

So I’ve made the jump from SME 9.2 to Nethserver 7.4 using the rsync-migrate process. Except for a small issue with the TLS certificate (addressed following my own how-to on the subject, though I hadn’t planned to use that for this installation), it’s gone smoothly. Mail is in place, the emails have migrated, I managed the Nextcloud data migration (a little tedious, but not too bad), so the big stuff is working. I’d like to get Horde back, but that will probably need to be a future project, as I’m traveling to .is in a few days.

Something I hadn’t thought about, though, was server-side mail filtering. SME had a panel (a contrib, I believe) that let you configure server-side filtering, which I used to put mail from various mailing lists into their respective folders. It was pretty handy, as it didn’t depend on any particular client being in use. I don’t see something comparable for Neth–am I just missing it?

I hope it isn’t time to brush up on my Procmail syntax…

Are you using any kind of webmail? Or groupware?
AFAIK roundcube can be used for filtering emails (folders, forwards…)

NethServer uses sieve filters that can be created with roundcube, sogo, webtop, thunderbird, etc.

Where is written this feature and howto on docs? :wink:

Not what I’m looking for–I do use webmail (currently roundcube, hoping to get Horde working), but I also use Thunderbird, the iOS Mail app, K9Mail, and perhaps others. Something that depends on using a particular client is a no-go.

I don’t agree. A client is an user interface, therefore using webmail for create filters is “the place where you have to do it” → the server, leaving possibilities to users to do the same thing (create filters)

These filters will act when the server will receive the messages, and i will find on every (IMAP) client the processed mail…

@stephdl You have shown us a mail(spam)filter-modul you adapted for nethserver at FOSDEM. Perhaps this is what @danb35 is searching for. Can you give us a link, I didn’t write it down at FOSDEM.

I see I should have been clearer. Many mail clients implement client-side filtering, which is what I thought you were referring to. In this situation, the client software does the actual filtering, so of course the messages only get filtered while that client is running. That, for the reasons I mentioned, would be a no-go.

OTOH, if the client has the ability to create/implement server-side rules, that would appear to do exactly what I’m looking for. I see the filtering option in Roundcube, but I don’t see a clear indication there of where the filters would be running.

It seems that any external program/client manages his own sieve rules. I cannot see sogo filter rules in roundcube, webtop or thunderbird. So they work server-side but not together.

Unless there’s something non-obvious about rspamd, I don’t see it addressing what I’m looking to do–this isn’t about spam filtering.

Do they? How can I determine that this is the case? I’m not especially concerned about seeing the rules from all the clients (though if the rules are on the server, and the filtering takes place on the server, it seems odd that I couldn’t see the rules through any compatible client). But if the rules are on the server, and they direct the MTA to deliver mail according to those rules irrespective of whether the (or any) client is connected, that would do the job (even if it would be a little clunky). But if the only thing that’s happening server-side is that the client is moving a message from one folder on the server to a different folder on the server, that’s a different story.

Sorry, the link was intended for @m.traeumner, not to help you. I just wanted to put everything in a post.

I tested it and set a filter in roundcube to move mail from my address to trash, disconnected roundcube, and after a test send I found the mail in sogos trash so this seems to be what you’re looking for…

mate, if you use SOGo, you can create sieve filters and those filters work server side, not on the client.

Any other client which can create sieve rules will give you exactly the same result and what you’re looking for

That sounds like a pretty definitive test–thanks. Still odd that a filter created with one client doesn’t show in others, but a lesser issue.

That’s not true, it depends on the client.
Roundcube can show filters created by all other clients.
Sogo can’t.
Tbird, can with the “right” extension.

Sorry but I created a filter with sogo, roundcube and thunderbird with sieve addon and couldn’t see any filter of another client.
Could it be because I am testing the new nethserver-mail2 ?
Is there a special setting in roundcube to show all filters?