What you are billed for
Personal, Pro and Premium are one price for one person; Business is €12 a user a month and Business Plus €20. Every plan includes extra addresses — 10 on Personal, 15 on Pro, 50 on Business — so billing@, support@ and hello@ cost nothing extra; each one delivers to the inbox of whoever you choose.
That is deliberate. Charging for every address makes a shared address a line item, which is how teams end up running everything through one person's inbox. A user is what actually costs something to serve; an address is a line in a table.
Storage and the outgoing limit are per plan: the published figures are totals across everyone on it, not per-address allowances. On Business storage is 250 GB per user and on Business Plus 1 TB per user, pooled across the team. Personal sends 100 a day, Pro 500 a day.
Did this not answer it?
Mail reaches a person rather than a queue. Include the domain and the exact error if there is one — it saves a round trip.
sales@ruber.me