GrinMark synchronization server needs a working uninterrupted connection to Office 365 to ensure stable and prompt synchronization of data. By default user passwords expire in Office 365 within 90 days. So you may want to make GrinMark user password to never expire. To achieve the goal follow these steps.
Run Windows PowerShell as Administrator. In the command line type the command and press enter:
A prompt will appear. Enter credentials of a user with Administrator permissions.
Execute the command to set GrinMark account password to never expire.
Set-MsolUser -UserPrincipalName email@example.com -PasswordNeverExpires $true