Hello,

I have an office where some users who have a lot of shared calendars and mailboxes make their Outlook crash. they will need to restart computer to get it working again. when they switch to other calendars or mailboxes, they have to wait 10 -15 minutes to see the calendar or a lot of times they have to restart computer. Network team got involved and said that network speed is fine. this only happens to users that have several shared calendars and mailboxes. Cached mode is turned On for all users on their Primary mailboxes, but not for any shared mailboxes. They are using Exchange 2012. I have some example of users below.

User 1 4 Shared Mailboxes, 19 Shared Calendars, OST Size 3.70GB -  Very slow access to shared folders.  Outlook freezes/crashes if they try to move any more than a few small emails from their inbox.

User 2 19 Shared Mailboxes, 14 Shared Calendars, OST Size 3.61GB - Outlook freezes especially when accessing shared mailboxes, only way out is to restart Outlook.

User 3 33 Shared Mailboxes, 26 Shared Calendars, OST Size 4.35GB Outlook freezes especially when accessing shared mailboxes, only way out is to restart Outlook.

User 4 1 Shared Mailbox, 36 Shared Calendars, OST Size 2.97GB Outlook Freezes random, especially when accessing other peoples calendar

User 4 6 Shared Mailboxes, 8 Shared Calendars, OST Size 12.6GB Slow access to shared mailboxes, calendars and moving emails between folders

.

• Edited by Fruiz367 17 hours 8 minutes ago

Hi,

I have a suggestion to you;

Disable Auto Mapping

Add-MailboxPermission -Identity <the shared mailbox> -User <the user> -AccessRight FullAccess -InheritanceType All -Automapping $false

Please look at the below link.

https://technet.microsoft.com/en-us/library/hh529943.aspx

Advantage of disabling Automapping

Once you disable automapping , you have to add manually each shared mailbox and shared calendar whenever you want under your mailbox. This will reduce the overload of outlook performance.

If you enable auto mapping, users who have full mailbox permission of shared mailbox and calender will show up under their mailbox. This will be very difficult to manage and maintain those mailboxes

Regards,

Joby