2.18 Set 'Require alphanumeric password' to 'True'
Information
Requiring users to include non-numeric characters in their passwords increases the strength of password security in your organization. Rationale: Not requiring alphanumeric passwords can make it easier for an attacker to correctly guess them.
Solution
To implement the recommended state, execute the following PowerShell cmdlet: Set-MobileDeviceMailboxPolicy -Identity Default -AlphanumericPasswordRequired $true