I am using Migadu (https://www.migadu.com/) For one domain and I am planning to move my Google For Domains domain over to it as well. It supports multiple domains and mailboxes (it prices on message volume inbound and outbound). For us our usage fits into the 19USD/year price point. Everybody else seems to charge per user/address.
It appears they charge for mailbox capacity. e.g. 5GB for the $19/yr. Is that total, for all users/mailboxes? Even 30GB doesnt seem enough, I have 10-12 family members on GSuite but I certainly won't pay £600/yr for them.
We send emails with photos/videos to the kids addresses so capacity needs to be a little more than 5GB shared for us, even if I kick all of the extended family off.
> it prices on message volume inbound and outbound
Sounds good on paper, but then you get charged for spam emails inbound. Is this the case? So you'll need to pay for unwanted inbound email as well as your outbound usage?