Recruiting Booster Email from Personal outlook

Hello,

can somebody please shed some light on the follwoing topic in the kontext of "Two-Way-Messagin" Recruiting Booster.

In the Documentation in states the following:

The marked sentence is not clear to me.

Is it possible for a recruiter to send an Email to a Candidate from their Outlook account directly, or does the sentence mean that all messages that should show up in Oralce need to be sent by the Vanity Email?

Would this mean, that Emails send from outlook directly, requires the Recruiter to have access to the Vanity Mail inbox directly?

Thank you in advance and kind regards