Hello everyone,

please let me introduce myself:

My name is Sebastian Schneider, I am a 25-year-old trainee from Germany. I was studying computer science at the local university, but had to drop out due to personal reasons (no money ). I
am now hired as a trainee by an international company.

I am attending vocational school twice a week, which brings me to the reason for this message:

The next week will be "Projects Week" in this school, meaning that groups of trainees have to
propose projects and the most interesting projects will have to be implemented by groups of
four to five trainees. This part already has been done and unfortunately, my project got
ranked high enough by my classmates, meaning I will be the SMP project leader by tomorrow morning.

My project description was:

As most people know, E-Mail is not secure. People are receiving malicious programs or spam via E-Mail every day. For a large company, an E-Mail sent to all users will require them to read and evaluate it, causing costs as high as 3 EUR per Mail, per Minute and per User. This means, any spam sent to
every average user (not too familiar with spam recognition) on the company accounts will cost the
company about 3000 EUR for every thousand users affected.

I propose, as my project, setting up an E-Mail Proxy-Server, which will retrieve eMails from another server, check them for malware (using a virus scanner) and spam (using white-/blacklisting or Bayes' Filters) and move any suspicious E-Mail to a spam-folder (which has been done by many freemailers, such as GMX.net), which can be checked regularly for false-positives.

Users should be able to define whitelists for any E-Mail which has not come through and senders should receive notifications about filteres E-Mails, so no vital E-Mail will be lost.

The project should be realized using only Open-Source or free software in order to keep costs as low as possible.

I was wondering if you could give me a hint which email-server should be used to accomplis this task, and if so, where I can find setup-documentation. I also would be glad to hear of any software meeting the project requirements that could be useful in achieving the goal of a filtering email proxy.

So, in general, what I am looking for is an email-server (POP3, and _maybe_ IMAP) which can retrieve eMail from a remote server (using POP3 or _maybe_ IMAP). The Server should be able to use a malware scanner (virus scanner) and Spam-Filter to block any potentially hazardous email and provide the sender with information on why his email was blocked and how to contact the sender to be whitelisted.

Unfortunately, the schedule is tight (one week, minus 2 days for writing documentation and a project presentation, which is to be held at vocational school on friday).

I am new to setting up servers in linux. I have started collecting software two days ago (links to website, that is). So far, I found 2 servers, (one of which is specified as "email proxy": Exim and Perdition.

I also heard about a software called "Spam Assassin" which seems to be using a Bayes filter to recognize spam, as well as an Open-Source-Virusscanner, whose name I forgot.

I would be glad if you could help me out here. I plan to use Mandrake 10 as a basis, but I also thought about HDInstalling Knoppix - which is about the easiest way to start I could think of.

Thanks in advance,
Sebastian Schneider