Need to fix 5 Common Errors of Outlook

Need to fix 5 Common Errors of Outlook:
- “Cannot open your default e-mail folders. The information store could not be opened. ”
- “Your Microsoft Exchange Server is unavailable. ”
- Office Outlook will not open personal folders or personal folders do not show up in Outlook.
- “The action cannot be completed. The connection to the Microsoft Exchange Server is unavailable. Your network adapter does not have a default gateway” or “Your Microsoft Exchange Server is unavailable”.
- None of the authentication methods supported by this client are supported by your server.
The above stated error messages with respect to Outlook are very familiar to me as I'm encountering with it very often.
Though, need your kind suggestions and help over this issue.
Appreciated.
