iOS 6: Exchange sync may use old password
In iOS 6 and earlier, your Exchange account can become locked if you change your Microsoft Exchange password without changing it on your iOS device.
To avoid this issue, please upgrade to iOS 7.
If you are using a device that does not support iOS 7, be sure to update your Microsoft Exchange account password on your iOS device immediately if you change your password on another device. To change your Microsoft Exchange password:
- Go to Settings > Mail, Contacts, Calendars.
- Tap your Exchange account.
- Tap the Account button.
- Enter your new password in the Password field.
If you change your Microsoft Exchange account password (using something other than your iOS device), your iOS 6 device will attempt to use your old password four times each time it tries to sync, and it may try to sync twice before notifying you that a new password is required. These attempts may cause your account to be locked if the maximum number of password attempts allowed is less than eight.
As a workaround, your Exchange or Active Directory administrator can raise the number of password attempts allowed for your account. One option is to configure a Fine-Grained Password Policy to cover iOS users. Within the Fine-Grained Password Policy, increase the LockoutThreshold to eight or more and decrease the value for ResetLockoutCounterAfter and LockoutDuration.
For more information about Fine-Grained Password Policies, see this Microsoft document.