Office 365 offers a native tool using ADConnect to sync your username and password in the cloud. I have come across whereby the forest has to be the same the primary email address which make it difficult in some cases as clients generally setup @local domain. There are also many pre-requisites which is require ensuring ADConnect compatibility and it is a pretty much a readiness check. I would recommend another application which is a simpler to get the same results of ADConnect.
This application is called IDSYNC. This can be obtained through Global Micro Solutions. This application is a simple setup and configuration. I would like to run through some of the base configurations of this application.
It requires a standalone server. The application is then installed on the standalone server. It uses a SQL database. The SQL instance is installed on the same server. Thereafter, agents are installed on the various Active Directory Servers. This application talks to the Active Directory objects and links it to the email address which is located on Office 365.
The Application allows as well as ADConnect to configure the Group Policy, Password Policy etc. which will can manage the users passwords. The Password resets are quite simple in how it works. When a password reset is done on Active Directory, it is then captured by the Agent, which is then transmitted to the SQL database. Data is then sent through to the Main IDSYNC system to complete the Office 365 password reset.
All connection is encrypted at source and destination. I would highly recommendation checking this application especially with the Office 365 coming in demand. Click on this link to know more about IDSYNC.