make me have a comment on the external sharing for [alternate email].
In case of performing an external sharing with one of my users, the e-mail address is registered in the part of one user's [alternate email] within a tenant. I can set the [alternate email] along with [Role]-[Edit] by selecting a user in Office 365 admin center.
When I attempt to perform an external sharing with this [alternate email],it is automatically replaced by the sharing for the user within the tenant registered as an alternate email.
I would say that an alternate email is an alternate email after all. I sometimes want to invite an alternate email as an external user, and therefore I do not hope it will turn out to be a substitute for different one with another role.
Having wasted a support call to Microsoft on this, trying to work out why some users external email addresses were resolving to their internal domain accounts.
This needs to be rectified, the alternative email is surely a backup for the account, not for resolving to your account.
It also allows for people to work out a relationship between a non work email and an work email, may not be a massive email, more of a privacy thing.