I recently moved mailboxes from an Exchange 2003 server (on SBS) to an Exchange 2010 SP3 server (on Server Standard 2012). Everything appears to be working fine except the users phones cannot connect using Activesync, It continues to ask for a password and cannot verify the server. SSL is enabled and the certificate works fine with OWA. I don't see any errors when connecting and the Exchange Remote Connectivity Analyzer shows a successfully connection. The feature is enabled on the mailbox(s) as well. Any ideas?
Basic authentication is enabled and no HTTP redirect.