iCloud Keychain – Safari Requires Password on macOS

The Exchange "autodiscover" settings changes the server URL to the WSDL resource.

So, mail.domain.com becomes: mail.domain.com/EWS/Exchange.asmx everytime you check for mail.

To fix this, you have to tell Outlook to stop asking for autodiscover settings using AppleScript editor:

tell application "Microsoft Outlook"
set background autodiscover of exchange account "NameOfAccount" to false
end tell

credit: http://www.officeformachelp.com/2011/01/exchange-autodiscover-workaround-for-advanced-settings/

To my knowledge, this is to put anything that can be synced with iCloud Keychain in a separate keychain. It is still technically part of the login.keychain, but kind of "partitioned" away in case you turn on iCloud Keychain and start syncing these items.

A lot of computer specific things are kept separate in the main login.keychain because having those show up on another Mac/iOS Device would cause it to misbehave since it is a physically different machine.

This is just based on my observation of macOS keychain. It only only started doing this when iCloud Keychain was introduced, and all the items in this second keychain will appear on other Macs and iOS Devices if iCloud Keychain is turned on. This second keychain changes it's name to "iCloud" when iCloud Keychain is enabled.