Toubleshooting Office 365 Email Client Issues

I get the following errors when trying to set up my Outlook profile:

"An encrypted connection to your mail server is not available."
"The connection to Microsoft Exchange is unavailable."

I keep getting prompted for my password when I try to open a shared folder, or I can open it but I see no new items. 

• Try deleting your Outlook cached credentials as described at Clear Outlook Cached Credentials in Windows Credential Manager

I often change the From field to send as different email addresses, and I noticed the default display name in the From field is incorrect.

• This is only a a display name that you see and does not affect the display name or return address that other see, but you change it by following the instructions described at Change your From field display name in Outlook in messages you compose.