Hi,
the problem we're seeing is that most phones experience connectivity issues to the users mailbox. Depending on model they get "Connection to server lost" or "message has not been downloaded from server" on individual messages. When users actually get their phones synced their outbound messages is being delivered multiple times. It affects all users.
Users mailboxes are a in a 3 node DAG and the CAS role is installed on these DAG members as well. Server OS is 2012 Std. Exchange is Enterprise 2013 sp1. If we reboot all servers the problem goes away. 10-15 Days later the problem always comes back.
My question here is not what the cause is but rather if we could get some help in trying to understand what may cause this? Troubleshooting steps would be highly appreciated.
When the problem is Active we have tried running testconnectivity.microsoft.com with Active Sync and syncing all messages in inbox without errors. No obvious errors in the eventlog on any of the servers. Just restarting the web application (or iisreset) helps. Only a reboot of the entire Windows server hosting Exchange helps. And we haven't been able to resolve the problem by just rebooting one of the servers, all 3 servers needs to be rebooted.
Thanks!
Erik, with many, many certs! ;-)