I have a Windows 2003 SP with Exchange Server 2003 SP2 on a QuadCore with 4GB of RAM and Windows 2003 standard. About 400 mailboxes. My questions: 1. That would put mailbox limit in this scenario? 2 .- For the clients that I have configured POP3, when you recived 4-5MB mail looks like it hung and we should remove this post?, I mean, to constantly repeat her previous post until it is removed blocking. 3 - Regarding the migration to Excgange 2003. How many servers are needed?, 1, 2 .... Thanks.

400 users on an E2K3 std server is something that i dont find good enough!....do you've any mailbox size restrictions in place?......Performance issues(like unresponsiveness etc) would result because of meagre resources available for exchange to process..... You're already on E2K3...are you talking about migration to E2K7......? Regards, Pushkal MishrA

I have no restrictions, I would like to know your opinion and see what the best solution. Referenctes to other places that you think is good. Migrate to 2010 Server.

Well to improve the performance you can try few things like... -Create a 3 GB switch in boot.ini file....that would provide an extra 1gb to user mode but there would less space for kernel mode, refer the link below http://support.microsoft.com/kb/823440 -If possible, build a separate FE send server so IMAP/POP client don't expose load on backend. -Make sure you've proper Antivirus exclusion in place on the server, refer the link below http://support.microsoft.com/kb/823166 http://support.microsoft.com/kb/245822 -You can also try to move few processes (Like temp and tmp files etc) to another disk group to ensure better performance. -Limit the mailbox size also however it is the item count that matter but having a size restriction encourages less item count, refer the link http://msexchangeteam.com/archive/2005/03/14/395229.aspx http://support.microsoft.com/default.aspx?scid=kb;EN-US;905803 -Make sure public folder with restrictions don't have many posts in them...here also item count creates performance issue, refer the link http://msexchangeteam.com/archive/2005/03/14/395229.aspx Where is exchange database sitting? is it on SAN or Direct attach storage…? Now as far as transitioning to exchange 2010 is concerned, you cannot perform an in-place server upgrade on an existing Exchange server. Instead, you must install a new Exchange 2010 server into the existing organization, and then move data to the new Exchange 2010 server. There are few things you’ll have to thought through like… Hardware (as e2k10 requires 64 bit OS) Backend Data storage (based on your IOPS) Roles (like mailbox, hub, cas etc) Refer the link, please http://technet.microsoft.com/en-us/library/aa998604.aspx