At work we are currently using Hosted Exchange by Microsoft. As all of our accounts were essentially locked out on the same day and required all of the users to log onto the webmail website to reset their passwords, with out pre warning.
After contacting MS Support they directed me to the following work guide.
The directions require you to set up powershell to use Microsoft Online Services Module. Next you need to issue the following set of commands:
- Connect-MsolService -Credential $cred
- Get-MSOLUser | Set-MsolUser -PasswordNeverExpires $true
Note that you will need to run this whenever you reset someones password or create a new user on the web based interface as it always defaults to the password expires false setting.