Determining the users connected in Outlook Online/Cached mode

At times we might run into checking the users how they are connected through online mode or cached mode during troubleshooting performance issues. If we have more number of users connected in online mode then we might need to look into the number of users connected through online mode as this could cause performance issues if we have more online users.

First we need to analyze and identify always users who can be used to connect online mode and the rest of the users can be connected through cached mode . Since cached mode stores the local copy of the user’s email and the OAB in the form of OST file.User no longer needs to  depend upon the network connectivity and the users latest information is available offline.

Probably for most of the users it is better to have the outlook in cached mode since end user will have better experience of reading the latest emails offline and would be able to update them periodically whenever they get connected. Users would be able to read important email even when the laptop is not connected in the LAN or WIFI.

Online mode can be used only in few exemptions where if we have a generic mailbox which has a secure sensitive data which should not be stored locally on any  common PC’s and should be available only for few users. Or if size of the mailbox is very large let’s say greater than 20 GB then it takes more time to update the information.  In those scenarios we can use online mode.

I have just collected few troubleshooting steps which we might think of doing if we are in a situation to determine the users connected in online and cached mode

To see users connected in Cached mode or online mode –

The first easiest way to identify this is through RPC Client Access Logs.

To achieve this goal, we can use Excel to open the RPC Client Access logs. RPC logs can be located in Client Access Server in the below Location.

(<Install Path>:\Program Files\Microsoft\Exchange Server\V14\Logging\RPC Client Access)

These logs would be in Text File. Copy them and open these logs in excel file do some formatting and filter. After filtering them the logs would look like the below screenshot.

RPC logs

We have 2 options classic and cached.Classic is for Online Mode and Cached is for cache mode.

Another way to achieve this is to use EXMON tool to identify the list of online/cached mode users


Download the exmon tool from the Microsoft site

Just proceed with the installation
Once the installation is done we need to go the installed directory and look for the file ExMon.reg,Double click on this file to add the required registry entries.

We might get warnings as below and just proceed with the adding the registry entries



We should get the below screen upon successful registration of the Reg keys


We have an option to check the users connected in cached mode as shown below in by clientmon Tab

cached mode


Also we have an option to see the client version and the client ip address in by user tab.




Apart from the above we can use the below script which will give only the Outlook Client Version and the computer name and not the ip address and the type of connection users are connected. It can be used only to find the type of Outlook version users are connected and the computer name from which they are connected.

Get-LogonStatistics -server ServerName| where {$_.ClientMode -ne “Cached”} | select-object FullMailboxDirectoryName,UserName,Windows2000Account,ClientMode,ClientName,ClientVersion,Identity | sort-object UserName -Unique| Export-Csv -Path C:\scripts\UserCount.csv -NoTypeInformation


Above steps can be used to troubleshoot the Exchange Performance issues and to identify the users connected in online mode in an Exchange Environment.

Also Refer –


Sathish Veerapandian

MVP – Exchange Server

One thought on “Determining the users connected in Outlook Online/Cached mode

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