Email Server

[Rink]

Hi,

I'm having a great deal of difficulty setting up a server to pick up email and filter spam, viruses, etc.

I'm trying to pick email up from a number of sources including pop3. However, I had one domain name MX configured to fire email directly at my static IP. This never actually worked and I have been unable to access my mail. I have tried various configurations including exim and postfix, but have been unable to convert their rather complicated man pages into a working email server.

I also need to have my users (who are using XP) to be able to send from Outlook (yuk).

I need details on how to set up samba to accept the outgoing mail and allow the incoming mail to be posted to the correct user.

Anyone know of a simple howto?

[Rink]

Anyone?

[stuart_b]

First, Samba doesn't do mail.

You need an MTA like Sendmail or Qmail. I think Knoppix has something called Smail, which I don't know anything about--presumably somewhere there's documentation on it, but if not it' an easy matter to install Sendmail or Qmail. Then, Webmin will considerably simplify setting it up (and has support for Sendmail or Qmail, another reason to go that direction).

Once you have a working mail server set up, the easy way to go would be to simply have your users log in with SSH (or telnet if your'e fool enough). Or install SquirrellMail or Usermin (user-oriented version of Webmin), and do webmail. This gets you out of having to figure out mail relaying restrictions--which you have to do if you want to let users use POP or IMAP.

If you need to use Outlook (or better Outlook Express, Eudora, Netscape/Mozilla Mail) you need to enable POP or IMAP, and figure out how to make your server not an open relay, or you'll soon get blacklisted, making the whole exercise futile. Or you'll get used by spammers, which is why being an open relay invites blacklisting. By the way, you generally have to enable IMAP for webmail, but it doesn't have the relaying issues using remote POP and IMAP clients does.

Anyway, Sendmail has a reputation for being difficult, but there is probably more official and unofficial documentation on it than any other MTA. And there are more tools to make it easy. Qmail is probably a close second--in just about all these respects.

[Rink]

Stuart,

Thanks for your reply.

Samba doesn't handle mail, but, as far as I'm aware it needs to have a list of valid users to handle user accounts.

I was advised to use Exim, which I was told was easy to configure: seems the info I had was way out of date and that the exim install has mutated to require dozens of configuration files, most of which are modified by scripts, and a good proportion of which seem to have no effect whatsoever.

I also have a real problem with the terminology.

What, for example, is the hostname? Is it the name of the server itself? is it the MX tab?

The relay stuff had me confused too. I previously worked for a company that was hacked (windows 2000 server) and used to relay spam, which, as you point out can and did result in blacklisting.

However, exim has steadfastly refused to relay from the local network (OE on XP), and no amount of tweaking of the myriad configuration files (see above) made the slightest impression.

Anyway, thank you for your efforts on this, I am sure that in today's environment of Spam, and malicious email, I can't be the only one wanting to set up an email server to filter nail and any help I get will, no doubt assist everyone else in utilising one of the undoubted strengths of linux.

[stuart_b]

And that's why I mentioned Webmin. It takes a lot of the work out of configuring server apps (including Samba, by the way), and by default has modules to support both Sendmail and Qmail. There is an optional module for Exim, but it only monitors the queue. One good thing about Webmin, compared to other things of the sort is that it does its magic by editing the standard config files, instead of writing dynamic ones. So it's possible to use it and still manually edit files, or use other config tools--as long as the other tool shows similar respect for the system.

Anyway, most of what happens in Sendmail is handled by one config file, and there is a lot of stuff written about it. The accepted way of configuring it these days seems to be to edit a subsidiary file which is then used to run a macro that actually does the edits, but backing up the file then manually editing it works--it doesn't verify your changes will work before you put them in place, but makes it easier to back them off if they don't. And Sendmail gets restarted after making changes (and if it fails to start, you did something wrong).

It used to be quite easy to test whether your server was an open relay. One of the anti-spam organizations had a server you could hit from your server with telnet, and it would try a bunch of SMTP exploits and tel the result. But apparently that server got hit by bad guys too often for them to keep it up, or they lost interest. (Both scenarios have happened with blackholes and other anti-spam services in the last several years.)