replacing NT/Exchg5.5/OWA with a linux solution

[hondarice]

The goal:

Replace an NT4 server running Exchange 5.5 with a linux alternative.

Web based access to mail, as well as MS Outlook 2000 interaction with the mail server via IMAP.


Possible? I'm aware of existing web based email utilities but am not familiar on the one's available.

Is there one solution that is common for people to use?


I also forgot to mention that this will have to interact with an NT PDC authenticating users. Is this possible? Or would a linux solution for authentication also be a good idea?

I'd like to go linux all the way to save licensing costs but am not entirely familiar with how functional linux solutions are within corporate environments that still use windows9x/2000 on the desktop.

Thanks,

HondaRice

[milanuk]

I think you shouldn't have much of a problem here. Basically any version of Linux, plus any one of the major SMTP mail transfer agents like sendmail, postfix, exim, or qmail, plus either UW (Univ. of Washington) IMAP or Cyrus IMAP, and then one of the many web-mail clients, like IMP or NeoMail, should do the trick.

As an example, mainly because it sounds like you might be planning on using this in a corporate environment, and thus could benefit from a (short-term) support contract during install/setup, you could use RedHat 7.1 + Postfix + Cyrus IMAP + IMP.

HTH,

Monte

[hondarice]

could desktop users with outlook 2000 still access the mail database using the IMAP protocol and what not like nothing had changed?

Contacts and the whole nine yards?

[milanuk]

As far as I know the main thing that probably won't be workable is the global address books and such. Groupware as such is kinda hard to come by in the *nix world... not impossible, or unheard of, but not common as fleas like in the M$ arena. I know there is an OpenLDAP implementation for Linux, so you can have a directory and whatnot, but I've never used LDAP on any platform so I can't really tell you more. You might try checking some of the other sources like the linux newsgroups, mailing lists for whatever distro & smtp program you choose, etc.

Good luck,

Monte

[jqpdev]

I'm looking to do the same. I have a wide area network with the following:
- NT v4 SP6a (30 servers spread across the WAN)
- Exchange v5.5
- Citrix
- Win98, Win ME, NT4 wks, Win2000 Pro, Win XP Pro. client PC's.
- 900 users

I would like to reduce the number NT4 Servers and replace them with Linux. Does Postfix have calendar sharing and global address books?

I'm not attached to using Outlook. I've evaluated Ximian's Evolution and my users could pick up that app quickly. Open Office, K-Office, Star Office, Wordperfect Office, or Easy Office will do for an Office suite.

Also... any advice on web content filtering (maybe use in conjuction with squid), or email filtering/spam filtering tools?

Oh... and one last thing... is there a way to get sendmail or postfix to store email in an SQL database like Postgress or MySQL?

Your assistance would be greatly appreaciated.

[m_hansford]

Recently I came across TUTOS on sourceforge.net. It's presently in beta stage so i wouldn't be inclined to deploy it in a production environment.

I am yet to have a play with it as I've got too many steps to go with Linux network management (not to mention Netware) yet but if it is comparable with Exchange functions then it could emerge as a solid app.

[NoahsMyBro]

I can offer some limited real-world experience concerning this topic:

My datacenter runs a Win NT4 SP5 & SP6a Domain. We have an NT Server running Exchange 5.5, and have used OWA since I was hired in mid-1998.

For as long as I've been with the company there has been a lot of dissatisfaction with OWA.

2 Weeks ago I started playing around with SquirrelMail as I have time. I've installed Red Hat 7.3, Apache, & SquirrelMail on to an old Dell Latitude - Pentium-2/233, 128mb, 6.5g hdd.

I have almost got it working well enough to publicize it and ditch OWA.

The remaining problems are:
A) It's unusably slow. I think I'm having DNS issues, but it may be that 128mb is simply not enough.
B) I haven't gotten it to display the Global Address List using LDAP. This is supposed to be doable. I think the PHP isn't working properly on the RH laptop.

BUT, this can be done and is definitely worth looking into. Another webmail client that looks appealing to me is called, simply enough 'webmail'.


As for spam-filtering, I've also just implemented that recently at work, and I'd estimate we've reduced incoming spam by 70%-80%.

All of our mail, incoming and outgoing, is relayed through a Linux box running sendmail. Essentially, our MX records point to the linux box, and it relays everythign to the Exchange server. Outgoing messages from the xchange server go to the linux box as well, where they are relayed to the rest of the world.

Sendmail supports Spam BlackLists. I added entries for 3 or 4 different FREE lists and voila! - my spam has been cut down noticeably. The only list I can recall right now is Spamhaus - www.spamhaus.org, but that's the one I started from when I began working on the project, and I found the other links from there.

-- Steve

[m_hansford]

Hey NoahsMyBro,

thanks for the info. Few questions/comments though...

1. What's been the dissatisfaction with OWA? Sure, it's trying to simulate an Outlook envt in IE (if I remember right) so sure there is going some performance/functionality differences. Are your users finding it cumbersome or is it difficult to administer or something like that?

2. Are you running your test server under X or from the command line. If you're running X, this could be part of the reason for the slow connection.

3. Have you checked the status of your NIC or switch? Perhaps it's running at 10Mbps. Strange how it happens but I come across it with switches every now and then. Despite being set for autonegotiate and the NIC is meant to be transmitting at 100Mbits, someow or other, the port functions at 10Mbits.

4. I wonder if upgrading your DNS to the latest BIND release (I think it's v.9) could help your speed.

Keep me posted on how it turns out for you. Sounds like a worthwhile project.

[NoahsMyBro]

From the top:

Originally posted by m_hansford

1. What's been the dissatisfaction with OWA? Sure, it's trying to simulate an Outlook envt in IE (if I remember right) so sure there is going some performance/functionality differences. Are your users finding it cumbersome or is it difficult to administer or something like that?


The main complaints concern it's poor handling of attachments, it's lack of speed (remember, the users are used to Outlook on their machine, and OWA is slower), and the cumbersomeness you mentioned. Obviously it won't be as quick as the local client, but the users still don't like it.

2. Are you running your test server under X or from the command line. If you're running X, this could be part of the reason for the slow connection.

[QUOTE]3. Have you checked the status of your NIC or switch? Perhaps it's running at 10Mbps. Strange how it happens but I come across it with switches every now and then. Despite being set for autonegotiate and the NIC is meant to be transmitting at 100Mbits, someow or other, the port functions at 10Mbits.


The test server has X installed, but I only used that to make the search for RPM modules easier. Except for the times I've been actively working on the machine to try and resolve issues, it sits at the command line prompt. Ordinarily X is not running.

As for the switch, I hadn't thought of that. I've been working on this laptop from my office, where it's running off of a 10mbps hub. I can't imagine that would make a big difference considering only one or 2 people are hitting this thing right now, but it's definitely a factor.

4. I wonder if upgrading your DNS to the latest BIND release (I think it's v.9) could help your speed.

I doubt it. I'm pretty sure there are DNS problems related to misconfiguration, not any flaw inherent to any of the software packages on the system.


Keep me posted on how it turns out for you. Sounds like a worthwhile project.

In all honesty I haven't had a chance to even look at the machine since I posted my previous message to this thread. But once I go further I'll update you guys. I also want to look into a couple of other web-mail-clients I've seen since installing SquirrelMail. I'll let you know how things turn out.

[magshernandez]

Did you ever get the whole package to work? We are trying to do the same thing. The implementation is different. Exchange 5.5 to Sendmail. Cyrus IMAP (although this is having problems), Open LDAP, fetchmail, evolution as an Outlook clone or Mozilla email client. The OS is Red Hat 8.0.

Thanks,

Magdalena