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kalliste 01-30-2003 10:14 AM

Red Hat 8.0 as a mail server
Im a linux newbie, with a strong MS Background, but please be gentle with learning!

I have a need to set up a mail solution over several bases and several domains.

I have set up a RedHat 8.0 Server with Sendmail, and got it working properly and its tested ok.

Now, I want to do a few things, and was hoping that people can answer a few questions so I can document this and sell the idea to my MD who wants to spend silly money on a group exchange option.

The Mail solution we need to use needs to do the following:

1. It needs to support several domains, as the group has a number of different company brands.

2. It needs to be robust and secure.

3. It needs to have the ability to handle up to 180 users, up to 10K messages per hour (I dont think it will be anything like this, but this is a nice round "more than I need" figure)

4. It needs to have some web access on it. (was thinking about Squirrel mail) and each base needs to be able to access a group address book, calendars...etc, the sort of thing you get with that nasty Outlook Web sure you know the thing.

5. Mail needs to be kept on server with people connecting to mailboxes (this is a later phase...for now POP3 will suffice.) I know sendmail doesnt do this, so if someone can recommend something else which holds mail on server (so it can be backed up) I would appreciate it.

we have a number of bases, with 3 main ones. I was thinking about setting up a server in each of the 3 main bases (where there are 85% of the people in the company), where each server is basically the same. Each base will have a couple of domains which it will manage.

The idea is that if one server falls over, or the mail cant be delivered to its primary MX, it will deliver to another one. Clients can then connect using the webmail (unless the DSL in that base has gone down, which is the reason it cant deliver)

I need the servers to replicate each other at none intrusive times, to update directories.... Such as overnight and weekends.

Has anyone had experience doing something like this before? Anyone got any documentation? Anything would help.

I have been an MS man upto now, but I want to start saving money as my department now has very low budget, and I dont want to spend it all on rubbish MS licenses...I also recognise a lot of problems having 180 people connecting to a remotely hosted Exchange Server from different bases....which is the other solutions a few other techies prefer (but I suspect they havent thought about it too much)

Im sure that i have bored you all senseless now. If you have made it this far, my thanks. If you can help, you will be in my xmas card list forever.

Thanks in advance.

mhearn 01-30-2003 12:50 PM

It sounds like Linux could easily do most of those things.

Mail replication I haven't heard much about, you can certainly synch things to a central location easily enough, but not sure how you'd have all three replicating to each other. Somebody else can probably fill you in.

You may want to talk to a Redhat or SuSE sales person about this. In particular, as you are prolly aware it's not just a case of slapping it on, you'd usually want to have them connected to the redhat network or the suse update service.

Redhat ATM are changing around their server lines. Currently Redhat 8 which could easily do this will be EOLd at the end of this year, but jeremy hogan has strongly suggested there will be a more stable and cheap server/service provided for people like you. It may be worth contacting Redhat UK about it.

Or you could just use Debian :)

Karanne 01-31-2003 06:46 AM

Mail server & replication
Nice to see a fellow M$ admin trying to escape the dark side! <g> I hope this addresses most of your points, although not in any particular order. Forgive me, it's morning, and I'm on my first pot of coffee!

I'm currently working on a RH 8 server for work with similar problems. I'm using Postfix (, though with a single domain (gov't law firm). I like Postfix because it only has two config files, and no M4 macros to run. Right now, we're using a very basic version of qmail on one of our AS/400 servers, and it's choking it.

I've installed Squirrel mail for WWW access, and open LDAP for user authentication. There is a plugin for Outlook's C&W feature that will allow LDAP authentication, but what you're looking for is IMAP. Beware, though that users being users, some of them will *never* delete mail. With the appropriate management blessing, you may want to set a big partition for /usr, and set user quotas. In total, I've got about 225 users in five offices. I've calculated disk space for 350 users and 100 mb each, to allow for expansion.

If you're not using Outlook Express, I would suggest that for a mail client for your Windows boxen, as it has built-in LDAP and IMAP support, and is included with IE for free (just for the boss!). There will be some pain for my users in changing from O98 to OE, mostly in learning the new proggie. What fun - I get to visit all the user's workstations and set up the exchange!

10k/hour is high, but doable. Regarding failback, all that you need to do is set multiple MX records in your DNS. The primary has a value of 10, the secondary has a value of 20, the tertiary has a value of 30.

Multiple domains aren't any problem. Look up 'virtual domains', and make the appropriate entries in your DNS. I'm sure that there's some way to ghost the server, and change just the particulars you need. Personally, though I'd host them all on one machine at HQ. We've had more problems with power and UPS's failing.

Backup: This is a temporary problem for me, as a tape drive with the capacity would cost more than the rest of the machine! Right now, I'm running a cron script at 23:00, which gzips /usr, and backing up to a W98 backup "server" with a 200 gb IDE drive and an IDE tape drive.

Replication. Did you look into mirroring software?

Group calendar. That's a problem I haven't solved either. For me, there are a couple of requirements: 1.) Multiple accesses to a person's calendar, so a secretary can add appointments to an attorney's calendar. 2.) The ability to sync with Palm. 3.) The BIG BOSS wants to be able to read anyone's calendar. Ideally, it would tie into the person's web/IMAP mail calendar.

User authentication: With Samba, they use the same NT domain logins and passwords that they use at work. I'm trying to convince the PTB to authorize individual passwords and password rotation, instead of a common password that everyone uses. (I know it's bad security. I inherited it, and it's something I'm fighting.) With the advantage of webmail, I think I can sell it from the liability standpoint of a cracker or spammer hacking someone's account. Any suggestions in that regard?

Anyway, I hope this helps!
karanne AT mindspring DOT com

rosko 02-06-2003 04:47 PM

I have read through your post and it seems lotus domino may be something you want to look at. It's a little costly but does all of the things you wish to accomplish, including replication. Each users mail files will reside on the server, which can be accessed through a notes client or pop3...imap whatever. Domino is probably one of the most secure platforms I have delt with in the IT industry. It is fairly robust, and just a suggestion. Very easy to configure also. You can download a "free" trial at for Release 6.

Good luck

dearsou 03-27-2003 04:11 AM

Hey p'ple..
Was browsing through ur mail archives.....n noticed that am doin sth p;'ple already have...So mebbe u can help me out..:)

Me running redhat 8.0 ,have set up postfix n courier-imap. Am currently authenticating only system users.... I need 2 migrate 2 virtual users....tried moving 2 LDAP (only for Mail sys users..not system authentication)....set up postfix accordingly n also changed courier-imap....But tis still not workin...

Does this have 2 do with PAM???

if anyone can plz send me some links or even me out!!!!


Soumya :(

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