By skyforbes 
Windows users may get the Task ‘Microsoft Exchange Server’ reported error (0x8004011D) prompt when trying to perform sending and receiving emails on Microsoft Outlook. The detail error message as below:
Task ‘Microsoft Exchange Server’ reported error (0x8004011D) : ‘The server is not available. Contact your administrator if this condition persists.’
Task ‘Microsoft Exchange Server — Sending and Receiving’ reported error (0x8004011D) : ‘The server is not available. Contact your administrator if this condition persists.’
Apply below resolution methods to fix this error and get your Outlook mailbox updated.
Content Summary
Solution 1: Enable Use Cached Exchange Mode when Offline
Solution 2: Create a New Outlook Mail Profile
Solution 3: Scan Malware in Safe mode with Networking using Windows Safety Scanner
Solution 4: Increase Maximum Allowed Sessions Per User via Registry Key
Solution 1: Enable Use Cached Exchange Mode when Offline
Below are the steps for how to enable Cached Exchange Mode for the affected Outlook mailbox…