Hi!
I have a strange problem in my Exchange 2013 CU9 environment.

Outlook clients (2013 fully patched, also 2016 and 2010) configured up with cached mode  and RPC over http hangs.

Steps to reproduce the issue:

1: Create a new outlook profile.

2: Set the client to use cached mode

3: start client and it freezes and drops connections now and then. Syncing of the largest folders never finishes.

Steps to fix:

1: Disable cached mode and client works fine.

We use a netscaler loadbalancer and if I point my client directly to one of the exchange servers cached mode works but not via netscaler. All other service works fine like owa, activesync.

Microsoft Connectivity analyzer gives no errors.

Also:

C:\Windows\system32>netsh int ipv4 show int

 

Idx     Met         MTU          State                Name

---  ----------  ----------  ------------  ---------------------------

  1          50  4294967295  connected     Loopback Pseudo-Interface 1

 25           5        1300  connected     Local Area Connection* 12

 24          10        1500  connected     ExchangeTeam

• Edited by Harmankardon Friday, August 21, 2015 12:16 PM

Hi,

According to your description, I noticed that the client works fine when you disabled cached mode. Only using Cached mode, the largest folder would freeze when syncing from server side.

Please confirm whether your mailbox is too large and the Mail to Keep Offline for cached mode is set to All in Account Settings. If that is the case, please set it to 6 months or 12 months to have a try:

https://support.office.com/en-nz/article/Change-how-much-mail-to-keep-offline-f3a1251c-6dd5-4208-aef9-7c8c9522d633

If the issue persists, please click Send/Receive tab to check the send/receive process and confirm if there is any error reported in cached mode.

Regards,

We have found a solution where we changed authentication methods on the Netscaler.

• Marked as answer by Harmankardon 21 hours 31 minutes ago