One thing is not very clear: how many custom domains can I have? Can I use 30 domains with 2 users each (random number, but i do need 3 domains).
How is the mailbox on phone? My major problem with email hosting is the lack of a decent mailbox service that's available on. Windows, android, linux that's either. One-time-purchase or open source. A monthly fee is fine if for unlimited users (I have a family)