Basic Questions

[dmwhite]

I am beginning to brainstorm the possibility of moving my current webmail solution on a shared general purpose webserver from Horde to open source Zimbra, and I'm wondering if you folks could answer a few questions for me...

Does Zimbra have its own MTA, or does it sit on top of something like Postfix?
Can you have multiple domains in a single Zimbra installation?
I'm currently using a Postfix / Dovecot / Horde solution. How hard would it be to migrate my users? I'd prefer not to have to change *anything* about my setup, other than the webmail interface (removing Horde, implementing Zimbra).

How much memory, cpu load, etc.... would you estimate would be needed for about 10 low-traffic (and low-email traffic) domains?

Thanks,
David

[lytledd]

Does Zimbra have its own MTA, or does it sit on top of something like Postfix?

It sits on top of Postfix

Can you have multiple domains in a single Zimbra installation?

Yes

I'm currently using a Postfix / Dovecot / Horde solution. How hard would it be to migrate my users?

Depends on the size of their mail boxes and the number of users. I've tried IMAPSync on my home server and didn't really think it worked well. I'm currently working on our move over, at my place of employment, we only have pop3, so I'm manually zipping up all the mail boxes, linking into the new account with Thunderbird and pushing mail out to the new setup via IMAP.

I'd prefer not to have to change *anything* about my setup, other than the webmail interface (removing Horde, implementing Zimbra).

It's not going to be as easy as that for the Admin.

How much memory, cpu load, etc.... would you estimate would be needed for about 10 low-traffic (and low-email traffic) domains?

The number of domains isn't the issue, it's the number of mail boxes you'll have to deal with.

We're running the NE version with around 18 domains on a Dell PowerEdge 1850 2U, 600GB drive space (SCSI 15000RPM) and 10GB memory. For 196 mail boxes at this time, I'm at 42% space. We average in the lower 25% CPU usage.

My home server with 3 domain and around 15 accounts, I run under VirtualBox with 2 CPUS and 4GB memory. I think it's pretty over kill though.

Doug

[xaqar]

It surprises me that IMAPsync didn't work well for you. We ran it to move our 8500+ mailboxes with very little pain. Most issues were caused by our old server being more permissive with what characters could be used in a folder name.

[aegrant00]

So if I run Zimbra 7 Open Source on a CentOS 5.6 machine with 512, have no more than 2-4 users connecting IMAP, and have a few domains relaying SMTP traffic in the middle of the night, should I get by OK?

[lytledd]

I'd suggest at least 1.5GB memory. There are a lot of processes and 1gb would be my bare minimum.

Doug

[dmwhite]

Thanks for all of the responses to my original post. I realize now that I asked and then disappeared. My apologies.

In answer to aegrant00, I would agree with Doug that 1gb is probably the minimum you'll have to have. I tried installing Zimbra open source on a VPS with 512mb, using all of the defaults, and the server fell to its knees. I'll probably attempt it again at some point, but after I have played around with Zimbra on a local dev server with a lot more ram, and have figured out what I need and don't need from the defaults.