CTX: Exchange is unavailable error on Citrix or Terminal Server

When a user opens Outlook on Citrix XenApp (or Terminal Server) running on Windows 2008, he received an error: “Exchange is unavailable”.

They are several reasons for this issue:

1) Network issues:

Check network connection. Check if network gateway is ok. Reset the network connection.

2) Cached Profiles:

• Check the date of cached profile folder for the user on the C:\Users folder. If the date is from previous days, ask user to log off and delete the cached profile. Also delete any temp folder, they are corrupted profiles.
• Check Profile List and delete key with .bak at the end in HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList. Compare users in task manager and delete profiles from not connected users too.

Note: you can enable a GPO to delete profiles when users log off from a session.

Open Group Policies Management console. Expand Computer Configuration, expand Administrative Templates, expand System, and then expand User Profiles.
Double-click Delete cached copies of roaming profiles, click Enabled

This GPO not always is working properly. A process lock the profile and some pieces of the profile still on folder. You can enable a GPO to delete profiles older than XX days when server is rebooted, to delete these profiles.

Open Group Policies Management console. Expand Computer Configuration, expand Administrative Templates, expand System, and then expand User Profiles. Double-click Delete user profiles older than a specified number of days on system restart and type amount of days.