I'm a sysadmin for a smallish ISP, and we have our own mail server (qmail, of all the godforsaken things) that serves mail for about 300 domains and 5000 users in total. It's running out of disk space, and we have to replace the hardware to make it bigger.
So, I built a new mail server based on Exim, which uses Dovecot for POP/IMAP, and is modified to use MySQL for user authentication both on the Dovecot end and the Exim end (when receiving mail to verify the existence of an account before accepting mail for delivery). This was all based on the HOWTO at struction.de, and after getting all the kinks worked out, everything was going swimmingly, until I got to the part where users need to be able to administer their own accounts, or at the very least the domain hosting customers who like to create/delete accounts on a frequent basis.
Vexim is basically a dead project, so I avoided that. Someone recommended Postfixadmin.
Now, while it almost works, it's missing a big, fat feature that breaks the setup I have: user-defined spam scores that are stored in the MySQL database in the user's account. Just as importantly, it seems that the entire design of the system needs to be built around Postfixadmin, instead of putting Postfixadmin on top. I've just designed the entire system backwards.
I've been working on this project forever, and now I just want to chuck it all and buy some software that makes mail servers work properly the way we need them. I'm also not about to spend the next month or six building a new version of Postfixadmin (with my design and programming skills, a bad one at that) or just even modifying the current one.
Is there a way out of this situation?
theres a open source isp tool, which probably is what you need.
Check: http://www.ispconfig.org/
But I think you will have to build your system from the ground, because this software only supports sendmail or postfix. Another question is, why do you choose exim and want to use postfixadmin. I don´t know this software, but I guess its for postfix :)
Another view of the problem is the following. These admininterfaces are in a certain way extremly specified. Not in the way you use them, but in the way how they need to be integrated in your enviroment. There are so many different scenarios in how to setup a mail server and the administration, that these systems need a very very specific enviroment they fit in. I would say it is nearly impossible to find a solution that fit your needs to 100%. The other way around, I bet also you don't find any commercial solution that fits 100% also. :)
I dont know exim, so I can hardly tell how you can get such a thing like user defined spam working, but I know postfix, and I would bet a great sum that you can customize Postfix to fit in your scenario. Personally I use sendmail and postfix and in the direct comparison postfix is much much more flexibel than sendmail can ever be (in its current version). So to clarify this again, I have no idea about qmail and exim and maybe these two mailservers are extremly good smtp servers, but I guess they are not as flexible as postfix if you want specialized setups. And in most cases there are simple ways to go, to solve complex scenarios or needs.
Maybe I get some downvotes for this post, but I never had a problem which was not solvable by postfix. I mean, you can build regualr expression based hash maps, how cool is that :)
I wish you the best luck to find your solution, hope I could help a little bit to clarify things a bit and show you another point of view.
I think the hate for qmail is a bit unjustified, its an excellent package for handling a lot of mail very securely. I would in almost all cases prefer it to Exim. That being said now that you have chosen a particular path and invested a lot of effort why not just hire a developer to tackle the feature requests you need? You say it boils down to one feature, which doesn't sound terribly complicated.
If you already have a mechanism for authenticating users against tables in the DB and you have a way of associating spam filters with those users, a front end seems relatively trivial. This is a good time to take a step back and look at how much the alternatives will cost versus some custom development, I think You will find that less than 40 hours will probably square you away and put you in a stronger position moving forward than completely redoing everything and be more cost effective.
Its also fair to say that there may not be any particular solution already existent that meets your needs 100%, and certainly not in the context of the work already done. There is an old expression that when you are a hammer everything looks like a nail, as a systems guy you may not be seeing the path of least resistance because you are working within your own skills and knowledge base. Reach outside of this to identify your other options. If you do end up doing a complete redesign despite this advice take a look at Cyrus Imap, as it is used effectively in some of the largest isp and univeristy environments and has a tremendous number of scalability and other advantages over a traditional exim/postfix/qmail db backed setup. good luck.
ISPmail tutorials are for you: http://workaround.org/ispmail
have you ever tried SMAD, wich is a webinterface for the mail system you used?! with the current version you alread can do the stuff you want. the dev is currently working on an update to adapt some new features. i'm sure he'll appreciate if you want to donate some money.
I don't think that Postfixadmin is the right place to be looking for a user-level spam score management thingo. Take a look at Maia Mailguard for managing spam scoring/whitelisting/washing the dog, and leave postfixadmin to the much gentler job of managing the existence of users.
(I'm using postfixadmin aswell, but doing offsite spam cleaning).
IMHO, the per-user spam settings should be in a webmail, not in the user/domain admin. Both Squirrelmail and RoundCube have plugins for this. There's also a (sadly outdated) patch for roundcube to integrate Postfixadmin-features for each user (like changing password, vacation message etc).
actually SMAD does exactly what you described. of course it's not that simple to use, but we are working on a new version. (the last release was about one year ago)
as the main developer hasn't much spare time at the moment, perhaps your employer want's to hire him to finish it to your needs.
Put amavisd-new to take care of fine-grained, user adjustable spam filtering.