If you plan to use or already are using Microsoft Online Services for your messaging system, you have to know that iPhones don’t totally support complex password.

Indeed, while working on a project to migrate to Exchange Online, we discover that password which contains ‘real’ exotic characters (such as €)are not supported by iPhone.

We were able to successfully configured the Exchange Active Sync service to iPhone BUT during the synchronization a pop up appears to ask to re enter the username and password. We had the confirmation of this issue by resetting the password with a less complex password.

This is a really a mess from the iPhone.