Apologies for the dry nature of this blog post, but I thought it important to give some background on why Outlook and more importantly Exchange often suffer performance issues. One of the main causes of poor performance is a user having high item counts in ‘Critical Path’ Outlook Folders and how Exchange deals with that.

Microsoft’s recommendations for Exchange 2007 are as follows:

“Ideally, it is best to keep the Inbox and Sent Items folders less than 20,000 items, and the Contacts and Calendar item counts less than 5,000. Even when maintaining item counts that are at or under the recommended maximum values, there are some operations which may still take noticeable time (usually this is approximately one minute). These operations include new sort orders and selecting folders for the first time. First time views of a folder can take even more time to generate the view. High item counts in critical path folders have an adverse effect on server performance because they are the most frequently accessed folders in a user’s mailbox. Other folders, especially custom folders that are created by end-users, can handle having larger numbers of items without having an adverse effect on the user experience because they are accessed less frequently. Be aware that, although the performance effect of having higher item counts in less frequently accessed folders is reduced, high item counts in these folders can still present intermittent performance issues as the number of folders like this increases, and the number of active users on the server increases.”
Source: http://technet.microsoft.com/en-us/library/cc535025%28EXCHG.80%29.aspx

It is important to note that not only the user with high items counts will suffer a performance hit, but also all other users on the server.

Microsoft are keen to address this problem with Exchange 2010, they are changing their recommended maximum limits to 100,000 items. This is mainly due to big improvements in disk I/O performance and larger memory caches.

Other ways to address the performance issues are to use Cached Exchange Mode. This passes the performance required to the client computer, from the server. All of the views, searches, sorts etc. take place on the Cached Mode’s OST file. Of course, this is not the answer for everybody and should the mailbox have a massive amount of items and the OST file also be massive, then the user will still experience performance issues.

Housekeeping is the real answer and users should get into the habit of deleting old mail that they do not need to keep. Filing email from ‘critical path folders’ (Calendar, Contacts, Inbox and Sent Items) into user defined folders is also a big help.

Exchange Server and Outlook come with an inbuilt address book (Global Address Book – GAL) that includes a list of every mailbox on the University’s Exchange email system. There are still other email systems at work at the University and at present the users on those system do not appear in the GAL.

As this is the case, it is important that the CAMA system is used as the de facto standard for finding e-mail address or telephone numbers. You can not guarantee that the person you are trying to reach has their mailbox residing on the Exchange system.

CAMA Interface:

The Global Address List is still not without merit, but it should be used carefully. As we have so many staff and students appearing in the list, there is quite a high chance that users have the same name. The GAL should contain information detailing a user’s school / service / course to help determine a specific individual.

Please note that the results have been blurred for the purpose of the screenshot.

1. Start typing the name of the individual that you are trying to find. The GAL will always try to navigate that list based on the user Display Name. This typically follows the Firstname, Lastname format, however due to legacy mail systems and number of users, there are users whose Display Name and email address starts only with their initials.

2. Use the scroll bar to find out more details. Most mailboxes have School / Service / Course information included to help distinguish users with the same name.

3. If you are experiencing difficult finding a user, try changing the search capacity. Changing from Name Only to More Columns allows the search field to look across multiple fields in a user’s account. This will let you search for all users with the same surname or same department for example.

4. Finally using the Advance Find function allows to specifically tailor your search for specific fields.

Outlook offers the function to remember previously typed email address. It stores these addresses in a Nickname cache (.nk2 file). As useful as this function can be, unfortunately Outlook also remembers addresses that you enter incorrectly.

When next typing the address, the erroneous address is offered as a choice. Without checking, it is easy to select that address and repeat the problem. Fortunately it is a simple procedure to remove the problem addresses.

When creating a new message, start typing the first few letters of the previously entered address.

Please note that the addresses have been blurred for the purpose of the screenshot.

The previously entered addresses appear. You can then use the cursor keys to navigate that list. Once the incorrect address is highlighted, press the Delete key on the keyboard. That address will be removed from the list.

NB. The NK2 file that controls what appears in the autocomplete list is associated with an Outlook profile. Should you change Outlook profiles, then a different/new NK2 file will be used.