Starting April 2018, many Outlook 2016 for Mac users started receiving the Mail cloud not be retrieved at this time error and getting credential prompts.

Mail cloud not be retrieved at this time error

Two possible root causes for this error are corrupted Keychain entries and a bug, which is currently being investigated by Microsoft. While an official fix is being impelemented you can try workarounds described below:

Option 1: Remove Keychain entries

If the corrupt Keychain entries are causing the issue, follow the steps below to remove them:

  1. Launch the Keychain tool: click Finder > Go > Utilities > Keychain Access.

    Keychain access

  2. Remove the following Keychain entries:
    • Exchange
    • Microsoft Office Identities
    • MSOpentTech*
    • Anything containing Intermedia servers, e.g. ****.exch***.serverdata.net

Option 2: Disable Autodiscover on the affected machine

Important: the workaround described here applies to Outlook 2016 for Mac users affected by a Microsoft bug revealed in April 2018 (version 16.12 or higher).

If the issue is caused by the aforementioned bug, then it can be resolved by stopping Autodiscover resolution for your email account on the affected machine:

  1. With Outlook still running open Script Editor: click Finder > Go > Utilities > Script Editor.

    Script Editor path

  2. Add the three lines below into the new Script Editor window and run the script by clicking on the Play icon or clicking Script > Run:

tell application "Microsoft Outlook"

set background autodiscover of exchange account "account name" to false

end tell

Note:

  • Make sure that the second line is prefixed by pressing Tab.
  • The account name value is usually the email address. Please confirm the account name in Outlook - the name of the account is displayed right above the Inbox folder.

Script

Option 3: Revert to Office 16.11 and earlier

Important: the workaround described here applies to Outlook 2016 for Mac users affected by a Microsoft bug revealed in April 2018 (version 16.12 or higher).

Refer to this Microsoft article for instructions on How to go back to Office 2016 for Mac 15.xx versions from 16.xx. Previous versions can be downloaded here.