We have numerous users on iPhone 5/6 - most the latest IOS with ActiveSync / Exchange 2010 SP3 Rollup 8, but it seems most of our iPhone users get a "Loading" screen when opening email (10 - 30 second), or at the bottom of the phone it locks up with either "Connecting" or "Sending" for a long time. I currently have a Samsung, and don't experience any issues. OWA and all the ActiveSync testing from Microsoft seems to look fine. Looking to see if any other users out there have had problem with the iPhones connecting to ActiveSync. We have a great circuit of 50Mbps Down 10Mbps UP that does not seems to have any issues, we also run a NSA 2400 Sonicwall. Users experience the same issues through different carriers (ie.. Verizon / AT&T, Sprint..) We have reset network settings, deleted the account and re added, but the problem still seems to occur.. There are no ActiveSync errors on the Exchange Server. I feel the problem started late last year when the IOS 8 came out (some users say it started around Nov 2014), even though Apple has put out 3 revisions, the problems don't seem to go away. Users must either reboot the phone, or switch Airplane mode On/Off to resolve. Client feels it is an Exchange issue, although I don't see any problems with the Exchange or networking.