In active directory, what is mailNickname used for?

Question

In active directory, should mailNickname always equal samaccountname? Or, should it always be equal to the mail property (minus the "@domain")?

My reason for asking is that we have recently changed everyone's primary email address to the first.last form and we set the mail property to the same. But, do we also need to modify the mailNickname property?

Thanks

Answer 1

mailNickName is an email alias. If you are using Exchange then you would need to change the mail address policy which would update the mail attribute. If you use the policy you can also specify additional formats or domains for each user.

Answer 2

No, it does not have to be the same as sAMAccountName. It just so happens that it usually is the same.