intermittent connection issues

We recently migrated users from Exchange 2010 to 2013 and now we have occasional issues with Outlook connections.
From time to time a user will get an error from Outlook stating that they cannot expand a folder from an "additional mailbox, or even their own archive mailbox directory.
This is an example of one of the errors that we receive.
"cannot expand the folder. The set of folders cannot be opened. Microsoft Exchange is not available. Either there are network problems or the Exchange server is down for maintenance."
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Adam FarageEnterprise ArchCommented:
I would first check the resource load on the servers, including the storage subsystem, memory and CPU. I personally would run experfwiz ( and then create a PAL report ( to review the resource consumption and see if anything is out of wack.

If that comes out clean, then I would look further and see if you have any issues such as out of date drivers or IPv6 turned off. If those are fine look at the networking side for any CRC incoming errors on the switchport, along with swtichport utilization and negotiation issues.

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Steven WellsSystems AdministratorCommented:
I would also check your Outlook anywhere and autodiscovery settings.
thom68Author Commented:
We did have IPV6 unchecked in network connections. I did enable IPV6 and we have not had reports of Outlook disconnecting. I want to watch and listen for reports of disconnections but i think that you are probably correct suggesting that IPV6 be enabled.
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