by Michael B. Smith, MCSE/Exchange MVP

In the earliest of Exchange Server versions, the absolute maximum size of a mailbox database was 16 GB. As the versions increased and the years passed, this limit was retained in Standard Edition, but was removed in Enterprise Edition.

With Exchange Server 2003 service pack 2, the Standard Edition limit was raised to 75 GB (although this took a registry modification). With the release of Exchange Server 2007, Standard Edition has no limit on mailbox store size. And, in fact, the Standard Edition can have up to five mailbox stores and five storage groups (which greatly simplifies a number of disaster recovery scenarios - with this feature improvement it is extremely rare to ever need to build a recovery server any more).

But what does that REALLY mean?

Just because you no longer have any artificial limits on the size of your mailbox store, does that mean it is OK to allow the store to grow arbitrarily large?

The answer, as you might have already surmised, is a definite NO.

You, as an Exchange administrator (or someone who wears that hat among many other responsibilities), need to plan for reasonably sized Exchange mailbox stores. What is reasonable? Good question.
To answer it, I'll need you to answer another question first: how much downtime can your business tolerate, while you restore an Exchange database from backup? Or, to put it another way, what is your SLA (Service Level Agreement) with your user community?

If this isn't a conversation that you've ever had with your management - you probably should. Mistakes, errors, hard disk failures, etc. are simply a part of life in the computing industry. No person and no piece of hardware are perfect.

In general, if you have practiced database restores with Exchange Server, you can anticipate that a database restore is going to take about 20% longer than a database backup. You also need to assume that it will take you some time to conclude that a database restore is necessary and get your head around exactly the procedure and process you will follow in order to do the restore.

So, to pick a number out of the air, let's assume that your Exchange mailbox store is currently at 40 GB and you do a full system backup at the same time you back up your Exchange server. Your backup takes two hours, to tape, and you figure that about half of that is from backing up Exchange.

You double the size of your message store, to 80 GB. Not too bad, you only add an hour to your backup. Now it's taking three hours.

You double the size of your message store, to 160 GB. Ouch. Now your backup is taking at least five hours and maybe longer - and do you have to use multiple tapes now? What does that do to your cost-of-backup and your tape retention schedule?

And in each one of these cases, just assume that a restore will, at best, take only an hour more than the backup. So, with a message store of 40 GB you are down for three hours. With a message store of 160 GB, you are down for six.

Your best bet? Keep the store to a reasonable size.

Microsoft recommends around 50 GB. If you need to go larger, add another store. And when you back up, back up each store in parallel, so they get done more quickly.

Oh - use reliable hardware. Do you know what the best kind of restore is? It is the one you don't have to do!

An Outlook user asks "I have done as you suggested by copying the entries from my calendar in my .pst folder to my calendar in the new profile but one thing that I noticed is that the reoccurrence settings do not copy over. I have to go back to each entry in the new profile calendar that should have a reoccurrence and set it. Is there a way that I can copy and paste the entries from my .pst to the new profile including reoccurrence settings? Both calendars are Outlook 2003."

I know this behavior occurs in Outlook 2007 as I had the same problem recently when a family member asked for a copy of my birthday calendar. The birthdays copied to the new calendar but I discovered the recurrences were missing. I believe this happens in all versions of Outlook, although I haven't had a chance to test it with older versions of Outlook because I don't have VMWare installed yet. (I installed Windows and all the applications I use, twice, and VMWare is last on my "must-have" list. I decided to try Vista x64 on my Tablet PC and after 4 weeks, came to the conclusion that the lack of drivers is too limiting. You'd think Microsoft would have 64-bit drivers for their software - I print everything to OneNote and missed that capability the most. I also discovered way too many websites require flash and flash doesn't work in 64-bit Internet Explorer. So I'm happily back to Vista x32 and while I "lose" a GB of ram, I gain a lot in usability. )

Now back to the calendar: This problem only happens in the Day/Week/Month view and is "by design". Sometimes you'll even get a warning that you can't move recurring appointments. Other times, nothing happens: the appointment doesn't move and you aren't told why.

If an appointment is configured to recur and you copy it to the same date and time, you'll lose the recurrence, no warning. If you try to paste it on a new date or time , nothing happens. If you right-click and drag the item to move it to a new folder, a warning comes up that says "Cannot move the items. You cannot move one occurrence of an appointment series to a different folder. To move a recurring appointment, you must move the original appointment or copy the single occurrence and move the copy." If you copy and paste or use Edit, Move to folder, you won't get a warning and the appointment won't move.

This issue is limited to the Day/Week/Month view and only affects recurring appointments you select in the calendar view. You can either open the appointment series and move or copy it using the Edit, Move to folder command on the open item (look for it on the Office orb menu in Outlook 2007) or switch to the table view to move recurring appointments between calendars. You'll want to use the a table view to move a large number of appointments - you can select all and move all of them at once.

Just when you thought it was safe to put DST issues behind you, at least until next fall, another one comes up.

From the Microsoft Daylight Saving Time & Time Zone FAQs Blog:

"Microsoft has learned of a possible change to the observance of Daylight Saving Time (DST) in Iraq that could impact customers using the Baghdad time zone which is also called the Arabic time zone (GMT +03:00). We have unofficial reports that the Ministry of Iraq has decided that the country will no longer observe DST as they have in prior years, which has historically taken effect on April 1, 2008. This may impact customers and partners in the region who use the Baghdad time zone, including military facilities and other entities engaged in business in or with the region. We are actively working with members of the military and US government agencies to confirm the change. At this time it appears that the change is likely but that could be reversed at any time."

ADVISORY: Potential DST Change in Iraq - Technical Guidance
http://blogs.technet.com/dst2007/archive/2008/03/25/advisory-potential-dst-change-in-iraq-technical-guidance.aspx

Stay updated on this and other time zone issues by visiting the Time Zone FAQ blog at
http://blogs.technet.com/dst2007/default.aspx

This is a combined quick tip because it requires both Outlook 2007 and Exchange 2007.

Outlook 2007's meeting request form may include a Suggested Times pane on the right side of the Scheduling assistant. The suggested times are supplied by the Availability service in Exchange 2007, so you'll only see it if you connect to Exchange 2007. If you use Exchange 2003 or earlier, the old "AutoPick Next" feature still works. Fortunately, Outlook is smart enough to know which feature your version of Exchange supports and displays it to users.

Currently in beta, Xobni is an Outlook add-in designed to help you manage your email. Among the features it offers are a instant search, email analytics, message threading, and the ability to manage scheduling and contacts. It works with Exchange, POP3 and IMAP accounts in Outlook 2003 and 2007.

William Lefkovics reviewed Xobni and has this to say: "Xobni Insight is a breath of fresh air for Outlook. It presents information in a different and meaningful way relative to Outlook. It provides a fast search mechanism that is extremely responsive. It analyzes emails to provide real-time relationship information with other addresses. It also presents a few handy reports for users to learn how they use email as well."

Read William's full review at http://www.slipstick.com/reviews/xobni.htm

Xobni Insight
http://www.xobni.com/