Unified mailbox and sender addresses

Good morning,

Apologies, I seem to be on the topics this morning… (-;

I am trying to create some kind of unified mailbox for myself, so one mailbox, where I can send/receive from all my email identities.

I’m hoping you can keep me right.

On the receiving side, I assume this is done from the admin panel with forwarders?

I assume identities/sender addresses must be created via the admin panel and tied to a mailbox before they can be used, or can they just be created on the fly in webmail?