Unable to connect to Exchange on iPhone An iPhone has previously been connecting to Exchange email without any problems.  Two days ago it stopped, generating an error: 


  Cannot get mail.  The connection to the server failed.



I confirmed the password was correct.
I confirmed that webmail was working.
I confirmed the phone was connected to the carrier, Telstra.
I deleted and recreated the account, but this issue remained.
I created my own account on the iphone, and received the same error.


Settings > General > About says:


Version: 4.2.1 (8C148)
Model: MB489X
Firmware: 05.15.04


Any ideas how to resolve this?
Faced same issue and found it is with Exchange server's user account settings. Initially Active Directory's authentication is successful but unable to retrieve emails. Issue sorted when went into exchange user account and Inherit AD permissions for my user account. Ola!