In one of the companies that we manage we are almost ready to begin Hybrid Exchange configuration. Now before i have installed the Dirsync i learn that all the company users has already been created in the O365 tenant. Reason being that they wanted to take advantage of the Office product that they already pay for. Fair Enough.
Now i cant remember, what happens when i do the sync. if the alias is not the same then i have dual identity. But if the users data are in fact the same what happens ?
Now i will do the id fix test, and set my sync point to an out with a test user that i have created on-prem and in cloud for this purpose to see what happens. And the work from there.
But still i would like your input :)