I will fill in a few blanks for now and chime in again when others have posted:
> Scenario: approx. 200 heavy users with a lot of 1-3MB attachments > (150 pop3, 50 imap4) Give us a total amount of data transferred per day..."a lot" is not specific. This also impacts your ISP bandwidth question below, and everything else. > 60 users located at site of IMail server rest in branch offices, all > using Outlook and/or web access, moving off of Exchange 5.5, IMails > web calendar will be used my 25% of the users. And IMail Web Messaging as well? IMAP4 and WM like CPU, as below. IMO, IMAP4 is frankly not worth continuing with--a good idea never really ready for prime time. What is the use case that dictates the use of IMAP4--users without laptops traveling to multiple corporate locations? WM can have real utility, on the other hand. Anyway, split out the data transfer indicated above: how much will be transferred via which protocol, and how much over each type of links? Remember, though you can't estimate it, that every page view in WM has HTML, too. > A new box will be dedicated to IMail though I'm not looking to spend a > fortune I need a stable platform for a business that relies very heavily > on email. If you have a budget, tell us and we'll try to fit (or call you crazy). Guessing won't help. Some orgs balk at $2500 for a new server, others $10K, etc. What's the Exchange hardware that you can repurpose (and how taxed was *it*?)? In an ideal world, you surround your mailbox server with smaller servers to distribute functional load (anti-spam server(s), anti-virus server(s), outbound mail gateway(s))--but with only enough $ for one box, recommendations will change a lot. > CPU? Not terribly important for basic mail protocols (SMTP, POP3). IMAP4, WM, WC do like more power here, especially when encrypted; Windows in general likes dual to take the edge off. Depends on all those metrics you're going to supply. :) > RAM? Fastest, most you can get. RAM and disk I/O speed are more important than CPU. > Disk Space? You tell us how big you want to let leave-on-server mailboxes get, and your expected rate of adding new users--that'll give you an answer. Pretty straightforward, compared to other questions. > Hard Dive? IDE or SCII - Raid5? SCSI, but not RAID 5. RAID 1, or 0+1 if you can afford it, with 128 MB cache if available. IDE RAID is acceptable, but also only with giant cache. As many dedicated spindles as possible to OS, swapfile, spool, mailbox volume(s), logs (re: that last item, I love making people ask questions). > OS? Win2k Server or Win2k Pro or XP Server. Pro/Workstation OSs will function but are a license violation. > Symantec Antivirus add-on or something else? Something else: Declude Virus, www.declude.com. > Spam handling? Glad you are aware of this need. You probably should offload this resource-intensive function to a bastion host (that is your actual MX, handling inbound mail processing/rejection). Len Conrad, who will surely speak up, has a cookbook for using BSD and PostFix for this purpose that he calls IMGate. >backup hardware? DLT, AIT, whatever will backup your left-on-server mailboxes in an acceptable window. >backup software? NTBACKUP is quite compact, if you don't already have a central backup server running elsewhere. Won't back up open files, though. > Firewall? Of course--you don't have one already? What's the deal? > fail-over hardware? You tell us: how long can the thing be down? Clustering is great if you can afford it; IMail works fine with MSCS. If you do cluster, you can have an active-active config where the secondary server runs MS SMTP as an outbound gateway, so the backup doesn't just sit there idle. > Dual nics? Inexpensive, so no-brainer. >Dual power supply? Not necessary if clustering entire servers, but otherwise self-evident, as redundant NICs. > ISP bandwidth? You'll have to give us more metrics and the remote locations' bandwidth, as above. -Sandy Please visit http://www.ipswitch.com/support/mailing-lists.html to be removed from this list. An Archive of this list is available at: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ Please visit the Knowledge Base for answers to frequently asked questions: http://www.ipswitch.com/support/IMail/
