Weird authentication with Exchange server

I'm using Evolution with evolution-mapi to access an Exchange e-mail server. It has worked flawlessly in the past, but recently it will fail to authenticate, asking my password endlessly. If I enter the correct password, it tells me that it is incorrect. If I enter an incorrect password, it closes the prompt, but fails to obtain the mail from the inbox (due to the truly incorrect password). I fixed part of the issue by pointing my client to the server's IP address rather than its hostname, but it will still occasionally fail to send/receive e-mail. EDIT: What I can do: I am able to ping the server via its hostname and IP address with no packet loss. Since this is an internal server (or at least I'm accessing it via LAN), I have no reason to use a FQDN. I am able to use the server for its other functions, namely a network-mountable directory where we store shared files for work. The server appears to be fully operable. I'm under the impression that this issue is specific to Evolution or the MAPI plugin, or at least the versions thereof available in Ubuntu 14.04. EDIT 2: It seems to be on and off whether a certain session of Evolution will properly authenticate. Also, each time I enter my password, I am given the option to save the password to my keyring, but it never seems to actually save.