Mailbox or alias: which do you choose?

Both give you an address. The difference is whether it has its own storage and its own password.

A mailbox

A full account with a password, storage and its own login. Needed for somebody who has to send and manage from that address.

An alias

A forward to an existing mailbox. No extra storage, no login. Ideal for info@, billing@ or a temporary campaign address.

When an alias is enough

If nobody needs to send from that address, and one colleague handles it. It is cheaper and uses no quota.

When you need a mailbox

If several people need access, if replies must come from that address, or if the history should stay separate when somebody leaves.

The classic mistake

Creating a full mailbox for every functional address. You end up with ten accounts nobody reads, each with its own quota and password to manage.